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- October 23, 2022
- PCB knowledge
- (0)
- 05 mins
A step-by-step guide to printed circuit board repair
Dealing with printed circuit board repair isn’t as simple as replacing components on a printed circuit board. It takes a great deal of knowledge and experience to diagnose a failure and even more experience to repair the damage that it causes. The following steps can help determine if a PCB is repairable.
Let’s have a detailed view of the printed circuit board repair process.
Can a printed circuit board be repaired?
The answer is yes, but it depends on many factors. Here are the most important ones:
When can a printed circuit board be repaired?
As long as there is no visible damage, or if the damage does not affect any of the components, you can repair your printed circuit board without any problems.
When cannot a printed circuit board be repaired?
If cracks in any traces or vias (the holes connect one layer to another), it will be impossible to repair your PCB. Also, if any components have been damaged beyond repair, they can’t be used again and will need to be replaced with new ones.
How do you diagnose a bad PCB?
The PCB is a key component of many electronic devices and is crucial to their functionality. Thus, it’s critical to recognize when a circuit board is defective and to replace or repair it when necessary.
Schematic or service manual
The first step in diagnosing a bad PCB is to pull out the schematic or service manual and see what components are on it. If one of those components is broken, it’s probably not worth repairing since users need to buy another. If all of them are good, then there’s still hope!
Signal generator
A signal generator can check for shorts in the traces (conductors). A short trace means two conductors are touching each other along their route through the board. A soldering error may have occurred, or one was cut off by accident (which would create an open circuit).
Oscilloscopes
Oscilloscopes are devices typically used to make it easier to display and analyze the waveforms of electrical signals. This essential tool enables the designers to track changing electric signals over time, which is crucial for figuring out why the circuit isn’t functioning properly. When testing circuit boards, an oscilloscope shows the required data.
What causes printed circuit boards to fail?
There are many different types of failure that can occur with printed circuit boards. These include:
Plating voids: These are areas where the copper has been stripped away from the board surface, leaving a cavity filled with air and moisture.
Copper too close to board edges: This causes soldering problems because there is not enough room for the solder to flow out onto the joint between components and pads.
Thermal voids: They occur when heat from soldering is not properly managed during PCB manufacturing or testing. Thermal voids can cause internal stress that can crack or fracture the PCB over time, leading to failure if not caught early enough.
Copper or solder mask slivers: These occur when a piece of copper or solder mask breaks off from the rest of the material and becomes embedded in a hole or on top of a pad, causing shorts between pads on opposite sides of a trace
Missing solder mask: This occurs when there is no coverage over pads or traces, making it difficult for the solder to adhere.
Acid traps: They occur when there is an insufficient amount of solder mask on the board or when there is excess solder mask left on a section of the board after manufacturing.
How do you repair a PCB?
Printed circuit board repair process is as follows:
- Attach the PCB to the work area, then remove the damaged components.
- Remove the solder and clean the track.
- Put the copper tape on the track and cover it.
- The joinery is soldered.
- Restore the through-hole on the circuit board.
- Install the component, then solder it.
- Remove any extra tape from the mended area.
What tools can be used while repairing a PCB?
The process of printed circuit board repair needs the following tools:
- Epoxy Repair Kit
- Pad Repair Kit
- Document for PCB Materials.
- Heatshield(Tm) Gel.
- Gold Replating Kit
- Through-hole Repair.
- Repair Materials.
How much does it cost to repair a printed circuit board?
Circuit board repairs typically cost $50 to $150. A new chip or capacitor costs less than $20 and soldering it in place only takes an hour, depending on the type of component that designers wish to replace.
How long does it take to repair a printed circuit board?
Printed circuit board repair typically takes 20 to 30 minutes. On average, a furnace control board lasts 10 to 15 years.
Considerations while repairing a PCB
Designers should consider before deciding to go ahead with printed circuit board repair.Cost of a new PCB
A designer first needs to consider the cost of a new PCB. The cost of a new PCB depends on its size and complexity. Also, if the PCB has some critical components like processors, memory chips, and so on, it will be more expensive than normal.Length of downtime while replacing the PCB
Another thing to consider is the length of downtime while replacing the PCB. Repairing a machine that needs immediate repair is better than replacing it with a new one as soon as possible.Cost of replacement parts
The cost of replacing damaged components on a PCB can be high if they are not readily available or there are no off-the-shelf replacements. In this case, designers may need to order custom parts from manufacturers and wait for them to arrive before fixing the device.Purpose of the electronic device
If the electronic device does not have any critical functions, designers may decide to replace it rather than attempt to repair it. If it has essential functions, designers may consider repairing it as long as doing so does not risk people’s safety (e.g., medical equipment).Conclusion
Printed circuit boards are a critical part of modern technology. They are found in everything from cell phones to computers to automobiles. However, these versatile boards can also be fragile and prone to damage, leading to intermittent failures or complete malfunctions. Fortunately, many ways to repair damaged printed circuit boards do not require sending the board back to the manufacturer or purchasing an entirely new unit.
Rather than replace PCBs entirely, a PCB repair enables the users to keep the design they’ve worked so hard on. Visit IBE’s website to learn more about printed circuit board repair. We can help you fix your defective PCB or PCBA.
