The demand for electronic devices powered by a PCB system has grown significantly over the years. As you can see, printed circuit boards are more complex than ever. With strict safety and quality regulations, PCB manufacturers are taking extreme measures to ensure PCBs perform as intended. However, this does not mean that the PCB never gets damaged or cannot be repaired. Do you want to know what the repair and return of a PCB entails? Read this post to find out your answer.
Let’s see the basic PCB cleaning and rework procedures and methods
Below are some steps for regular PCB Rework and repairs.
Cleanliness: PCBs can contain surface contaminants that can seriously affect electrical properties and physical components such as soldering, coating, and bonding. These surface contaminants are cleaned by the automated cleaning process or by the use of detergents.
Corresponding Paint Removal: Removing conformal paint is often the first task in a PCB repair process. Compliant coatings are defined as protective chemical coatings that protect electronic circuits from harsh environments containing many chemical contaminants. The PCB is coated and insulated to protect it from corrosion or, in some cases, to hide what’s underneath. This deletion can be done quickly in several ways. However, it is essential to understand the type of coating before proceeding with the method.
After determining the type of paint, remove it in one of the following ways:
- Solvent Method: This procedure uses a solvent to remove the paint. This procedure is ideal for removing the total coating on a weld resistor.
- Peeling Method: This paint removal method is ideal for removing RTV silicone or other thicker rubber coatings.
- Thermal Method: This method uses a cold local heating method to remove the thickened layer of the PCB.
- Scraping method: In this method, the scraping tool is done with a scraper for dental reasons.
Coating Replacement: As the name suggests, this procedure defines the various methods and coating of printed circuit boards to replace solder masks at the BGA site.
Baking and Preheating: The reason for baking PCBs before rework is to remove all moisture from the plastic part of the component. When the SMT component passes through reflux, the element heats up very quickly, converting the water into vapor. This expansion renders the plaque paralyzed.
This action helps the manufacturer prepare for subsequent operations.
- Baking: Whenever possible, PCBs should be baked before soldering or other operations to avoid damage to blisters and other chips. The support removes absorbed moisture.
- Preheating: Preheating facilitates adhesion of subsequent materials and effectively performs welding/loosening operations.
Bow and Twist Repair: A bow is defined as the spherical bending of a plate, but a twist is a deformation of one of the corners and the other. If the circuit board is affected by warping or bending, the circuit board may need to be removed to make it look good. The bow and twist method is designed to reduce the deformation of the printed circuit board. This method is best suited for GF or GE substrate materials with a glass transition temperature below 125 degrees.
Conclusion: The instructions above are just the essential rework and cleaning procedures used by a PCB assembly service. It is necessary to check the credentials of the PCB assembly service provider before contacting them to work. Absolute PCB is one of the leading PCB rework and repair service providers that offer comprehensive PCB Rework solutions.