Rework station is a machine which blows out hot air with precision and is used to either heat ICs (Chips) or to replace them. Many of the times, ICs get de-soldered or loose some of the connections with the circuit board causing related faults. For e.g., if the IC (Integrated Circuit) is for distributing power in the PCB (Printed Circuit Board) and if it gets dry soldered (looses some of its connections with the PCB), it may lead to the cell phone not powering on. If the IC is related to sound, there will be no sound. This is more common in BGA ICs, while it was not as frequent in older SMD ICs. It is also used to solder any soldered electronic component on the motherboard like charging ports, microphones, etc. Some of the parts can get fixed with both soldering iron and rework station. In such cases, the technician uses the machine he is more comfortable with!
The reasons for ICs getting dry soldered are:
- Repeated heating and cooling
- Handset falling down with a high jerk
- Long period of time (wear and tear)
In such cases, technicians all over the world open the gadget be it a cell phone, a tablet, a laptop or the motherboard of a computer and heat the particular IC on its circuit. Most of the times, heating the IC solves the problem.
If the problem is not yet solved, there are 2 other options or steps to fix it:
- To remove the IC, reball it and fix it again. This option is rarely used by technicians and tried only if a new IC is not available. If the problem gets fixed, it means the balls below the IC may have become short-circuited. And if the problem is not solved, you will have to replace it
- Replace the IC. If the fault goes away, it will mean that the older IC was faulty.
The above explanation was necessary to come to the topic that is how to use a rework station.
The rework station is also called as SMD rework station and BGA rework station. It is also called a blower or hot air gun in slang language by technicians even though they are 2 different tools. It now-a-days also comes working on infrared technology. The main advantage of an infrared machine is it does not burn any plastic part, if it is nearby while using it!
You have to keep in mind to set the below 2 settings properly:
- Heat: The temperature mostly used is between 300 degrees to 400 degrees according to the IC’s size. If it is an analog one having no indicator or display having just knobs, the knob of heat is kept on 3.5 setting.
- Air: The air setting is kept on a little above the minimum. If more air is used, it may damage or remove the neighboring parts and if no air is used, it may lead the coil inside the handle to burn. So you have to keep it to a setting so that a little bit of air is coming out along with the heat.
The above 2 settings may also vary according to the job and the situation. Also you have to select the appropriate tip either broad or narrow according to the job.
You have to use soldering flux, which is a kind of liquid paste which is applied at the edges of the IC before heating or removing an IC.
Now, when you are ready with all the settings and have applied the flux, you just have to switch on the button of the rework station and move its handle such that the tip where the heat comes out in a circular motion inside the edges of the IC. Keep on moving till 2 to 3 times if you wanted to just heat the IC. And if you want to remove it, keep on moving till the IC loosens from the board and then lift it with tweezers. Do not try to pluck it out forcefully if it hasn’t loosened as it may damage the points below on the board.
Note: It’s better to practice on dead circuit boards and see more videos of professionals on youtube, before doing this procedure on live working boards, if you are a DIY type of person and do not know how to go about it. We also advice you to seek professional practical training, after reading this guide so as to do the entire procedure properly.