Previous article SHYSEMI introduced the 0-Base Tutorial Installation Tips for MOSFETs. In this article, we will discuss the matters that need attention when disassembling MOSFETs.
MOS Field Effect Transistor Disassembly Process
(1) What aspects should be noted when disassembling MOSFETs?
MOSFETs are small glass tubes and are prone to cracking. Therefore, when disassembling, be very careful. When prying, use gentle force and avoid touching the surrounding components. If there are adhesive chips, avoid them. During blowing, the wind gun should not stay for too long.So, Wind gun temperature adjustment: Set the wind gun to 320 degrees and 1st speed.
(2) When prying the MOSFET, use a sharper blade. Place the blade under the MOSFET and use your fingers to apply a little force upwards. Keep blowing with the wind gun and wait until the solder melts. The MOSFET will naturally fall off.
(3) MOSFETs are adhesive chips. When removing them, it is necessary to remove the adhesive from the motherboard. Be careful not to exert too much force, otherwise, some will fall off. Use tweezers to gently scrape the adhesive. Or use a slanted-edge knife to scrape the adhesive. Clean all the glue on the solder pads of the motherboard thoroughly.
(4) For small chips, use the tip of the soldering iron to scrape the adhesive.
(5) When disassembling MOSFETs, soldering is also required. Use a paper towel to absorb the excess solder paste on the scraping tool (try to make it as dry as possible). Wash the soldering net clean (no foreign objects in each small hole). Place the MOSFET on a piece of paper towel and align it with the soldering net. Apply solder paste evenly and clean it thoroughly. Then wipe it back and forth with a lint-free cloth.
Adjust the wind gun to 280 degrees, turn off the wind speed, and slowly move the wind gun from far to near on the soldering net. When removing the soldered part, be careful. Use tweezers to gently push from top to bottom at the solder beads. Add a little soldering oil when removing. Blow with the wind gun to wait for the solder beads to return to their original position.
(6) When installing MOSFETs, there are foot positions. On the back of the MOSFET, there is a small dot called the first foot. When disassembling, it is necessary to look at the direction. If you forget, compare with a board. If there is no board, look for the direction in the drawing or the position number diagram.
(7) Put a little soldering oil on the soldering pad. Too much soldering oil will shift. Place the MOSFET in the soldering pad on the motherboard, position it properly, and set the wind gun temperature to 320 degrees and 1st speed. Align the MOSFET with the soldering net and apply solder paste evenly. Clean it thoroughly and wipe it back and forth with a lint-free cloth.
Adjust the wind gun to 280 degrees, turn off the wind speed, and slowly move the wind gun from far to near on the soldering net. After soldering is completed, be careful when removing it. Use tweezers to gently push from top to bottom at the solder beads. Add a little soldering oil when removing. Blow with the wind gun to wait for the solder beads to return to their original position.If the MOS transistor resets automatically, it indicates that the soldering is correct.
(9) After the motherboard cools down, use cleaning water to clean the motherboard.
The correct steps for disassembling MOSFETs can extend the lifespan of the components and maintain the performance of the circuit. If you have any doubts, you can consult professional technicians or refer to the specific guidelines provided by the component manufacturer.