PCB News - Circuit board copper foil repair method

Circuit board copper foil repair method

The copper foil is broken due to improper operation of the circuit board. If you don’t want to remedy it, the cost of scrapping a PCB is not small. Therefore, in order to reduce the loss, we can do flying wire treatment at the copper foil fracture, that is, use the copper wire to link the broken sides. Just connect the line

If it is taken off a little, it is recommended to use a knife or other small sharp tool to scrape the insulating varnish on the copper foil a little, as long as the copper is exposed, and then connect it with a little tin.

1. Wipe the dirt and dust on the copper foil board. If it is severely corroded and oxidized, use fine sandpaper to wipe it lightly.

2. Add a little rosin solder paste to the soldering point

3. Insert the component, dip the solder wire with a soldering iron, and solder.

4. The copper foil can be soldered in advance

5. Weld the broken part with copper wire

The remedy for the copper foil of the circuit board in the mobile phone repair

In the process of repairing mobile phones, the copper foil of the circuit board will often fall off. The reasons are that the maintenance personnel often encounter the copper foil being removed due to unskilled technology or improper methods when blowing and replacing components or integrated circuits. ; The second is that part of the mobile phone corroded by falling water, when cleaning with an ultrasonic cleaner, part of the circuit board copper foil is washed away. In the face of this phenomenon, many repairers have nothing to do and often judge the mobile phone as a "dead phone." So how to effectively restore the copper foil connection?

1. Find data comparison

Check the maintenance information to see which component's pin is connected to the pin where the copper foil is dropped. After finding it, connect the two pins with enameled wire. Due to the rapid development of new models, the lagging maintenance data, and many mobile phone maintenance data errors, there are also certain differences compared with the actual PCB products, so this method is subject to certain restrictions in practical applications.

2. Find with a multimeter

In the absence of information, a multimeter can be used to search. The method is: use a digital multimeter, set the gear position to the buzzer (usually a diode gear), use one test pen to touch the pin of the copper foil that has fallen off, and the other test pen to slide the other pins on the circuit board. When the buzzer is heard, the pin that caused the buzzer is connected to the pin where the copper foil falls off. At this time, you can take a suitable length of enameled wire and connect it between the two pins.

3. Re-soldering

If the above two methods are invalid, it is possible that this foot is empty. But if it is not an empty foot, and you can’t find out which component pin is connected with the copper foil drop, you can use a blade to gently scrape the copper foil drop of the circuit board. After scraping the new copper foil, you can add it with a soldering iron. Lightly lead the pins out with tin and solder them to the desoldering pins.

4. Control method

Under conditions, it is best to find a circuit board of the same type of normal machine to compare, measure the connection of the corresponding point of the normal machine, and then compare the copper foil that is disconnected from the connection failure.

It should be noted that when connecting, it is necessary to distinguish whether the connected part is a radio frequency circuit or a logic circuit. Generally speaking, if the logic circuit is disconnected, it will produce side effects, and the radio frequency connection often produces side effects. The signal frequency of the circuit is high. After connecting a wire, its distribution parameters have a greater influence. Therefore, it is generally not easy to wire in the radio frequency part. Even if the wire is to be connected, it should be as short as possible.