Printed circuit boards are a critical component of electronic devices. That’s why it’s so important that they function properly at all times. Issues with PCBs can occur during the manufacturing stage or when working with these boards. Fixing these faulty issues requires special equipment and expertise in rework in soldering.
What is Reworking in Electronics?
Rework is a process where a printed circuit board assembly is repaired or refinished by desoldering and re-soldering SMD or surface mount components through the printed circuit board itself or (THT) through-hole technology components. In essence, it’s the act of reprocessing a product that is non-compliant due to a defect so that it assures compliance of the product.
Rework in soldering is performed by hand or with rework stations by specially trained personnel who can identify the defects and then carry out the process. Some of these defects are a result of soldering mistakes, bad solder joints, incorrect placement of components, high voltage current exposure, assembly mistakes, and electrical defects from electrostatic discharge.
Rework may involve one component or several components. If several are involved, each component must be worked on one at a time without damaging any of the surrounding parts or the printed circuit board. Parts not being worked on must be protected from any potential damage and heat.
Is Reworking the Same as Soldering/Desoldering?
Reworking and soldering both include the process of soldering but when it comes to the two stations, they differ in their range of use. Soldering is a process all in itself but is only a part of the reworking process.
A soldering station is ideal for precision work such as through-hole soldering. A rework station works with any component and is better for less sophisticated work such as melting solder in larger areas.
A heat gun is the main part of a rework station while the soldering station features a soldering iron, a stand for the iron, and a sponge. The size and weight of rework stations are greater than soldering stations. Soldering stations are more portable and easier to control.
Soldering stations have direct contact with the components they are soldering and are ideal for attaching two components at a small point. A rework station doesn’t direct all its heat in one spot but in larger areas.
How Many Times Can You Rework a PCB?
There are several things to consider when determining the maximum number of rework cycles. Some of these factors include PCB design, material & components, and the number of heat cycles the board has already experienced.
A design with hearty laminates, robust construction, and larger pads hold up better under more heat cycles. Factor in the temperature limit of the material, components, and number of previous heat cycles and the number of rework cycles of a PCB is typically three.
Types of Rework Stations and How to Rework?
There are also BGA, LGA, and SMD rework stations. BGA stands for ball grid array and is used for integrated circuits with a design of surface mount packaging. LGA stands for land grid array that is surface mounting technology that solders wireless modules into integrated ones. SMD or surface mount device is a rework station that features a heating element, an enclosure, and a toolset and is used to remove and replace defective parts on circuit boards without damaging the other parts, mount new components onto circuit boards, and for soldering & desoldering.
The basic concept of rework in soldering is to remove the faulty component by heating the solder joints between the component and the circuit board. Remove the component or part while the solder is molten. Remove residual solder by heating to melting temperature. The new component is then soldered onto the board.
Do I Need a Hot Air Rework?
A hot air rework is ideal if you have small jobs that need to be completed quickly. The hot air gun will melt the solder so you can remove components from old circuit boards.
A hot air rework also doubles as a soldering station so you can desolder and resolder simultaneously. Another advantage of a hot air station is that you can avoid damage to other areas of the circuit while you work. You can solder and desolder more efficiently and in less time.Lab Pro offers a large variety of rework stations. For over 40 years, Lab Pro Inc. has been committed to delivering the highest quality rework stations, hand tools, chemicals, lab equipment, distance learning kits, lab supplies, and cleanroom PPE apparel to medical device companies and laboratories worldwide. To learn more, visit the biggest Lab Supply showroom in California, or contact us online or at 888-452-2776.