Chip components on printed boards are new micro and small components without leads or short leads, which are mounted directly on the printed board and are special devices for surface assembly technology. Chip components have the advantages of small size, light weight, high mounting density, high reliability, high vibration resistance, good high frequency characteristics, and strong anti-interference ability. They have been widely used in computer equipment, mobile communication equipment, video cameras, color TV high-frequency head, VCD and other products, and are developing rapidly.
Commonly used chip components are: (1) chip resistors (2) chip capacitors (3) chip inductors (4) chip diodes (5) chip transistors (6) chip small integrated circuits.
These chip components are very small, fear of heat, fear of touch, some lead feet a lot, difficult to disassemble, bringing great difficulties to the maintenance, and thus the scientific method of disassembly is very important, the common method of disassembly is as follows.
Optional special "∏-shaped" soldering iron head, "∏-shaped" head notch width and length can be determined according to the size of the removed parts, special soldering iron head can be removed on both sides of the lead foot of the solder melted at the same time, so it is convenient to take down the removed components. Can also be disassembled using a homemade soldering iron tip.
Self-made method.
Select a section of the inner diameter of the iron head with the outside diameter of the purple copper tube, one end with a vise clamp flat or hammer flat, drill a small hole;
Then use two pieces of copper plate or purple copper tube longitudinally cut open and flattened into the same size as the length of the disassembled parts, and drill small holes;
Frustrated end face, polished clean, and finally assembled with bolts, set on the head of the soldering iron, heating, tin, can be used.
For the two solder joints of rectangular sheet components, as long as the soldering iron head knocked into a flat shape, so that the width of the end face is equal to the length of the components, you can simultaneously heat and melt the two solder joints, take down the sheet components.
Tin-absorbing copper mesh is made of fine copper wire woven mesh tape can also be used instead of metal shielding wire or multi-stranded flexible wire of the cable. The use of the net will be covered in multiple pins, coated with rosin alcohol solder, heated with a soldering iron, and tug the net, the solder on the pins that the net is adsorbed. Cut the attached solder wire, repeat several times, the solder on the pins gradually reduced until the pins are separated from the printed board.
When the multi-pin components with anti-static soldering iron heating solder melting, with a toothbrush or oil paint pen, paint brush, etc. to clean the solder, but also quickly remove the components. Component removal, should promptly clean the printed board to prevent residual tin caused by other parts of the short circuit.
This method is applicable to the removal of chip-mounted integrated circuits. With a suitable thickness, a certain strength of the lacquer line, from the inside of the integrated circuit pin gap through the person, one end of the lacquer line fixed in a suitable position, the other end held by hand, when the solder melted, pull the lacquer line "cut" the solder joint, the integrated circuit pins will be separated from the printed board.
Solder suction device has a general suction device and tin soldering iron two. Ordinary solder sucker use when the piston rod of the sucker, to be soldering iron will be removed when the solder joint melted, the sucker nozzle close to the melting point, press the release button of the sucker, in the sucker piston rod pop back at the same time, the molten tin sucked away. Repeat several times, can make the removed parts and the printed board separation.
The tin-sucking soldering iron is a special tin-sucking tool assembled with a common tin-sucking device and a soldering iron, the usage of which is the same as the common tin-sucking device.
It should be noted that the local heating process to prevent static electricity, the power of the soldering iron and the size of the iron head to be appropriate.
