Welding of components
1. Welding requirements with conventional welding processes
Components of the welding, the main note is: master the heating time, using the appropriate temperature and good operating action. Different components of welding, in different temperatures, air flow and other environments, the use of different soldering iron and soldering iron, to master the three aspects of the skills are also different, which requires us to work in a lot of practical exercise And improve
Welding should be the first component pins, PCB pad oxide removed, if necessary, the first on the tin, inconvenient to remove the application of oxide blade scraping its lead see bright after tin, or electric iron Contact with its pin, while heating side with solder melting, and with the tip to scraping back and forth, which can ensure the quality of welding, but to note that a continuous welding time can not be too long, so as not to damage the components, wire insulation, Components of plastic stents, parts. Especially their long-standing spare parts, the pin will be oxidized black. If it is in the case of electronic production, PCB pad may be due to prolonged exposure and serious oxidation, need to use the blade to scratch the welding.
Depending on the different components to control the heating time, welding will be the same time the soldering element components and PCB pad pad, in about 1.5s after the solder wire into the three contact at the melting point until the appropriate amount and welding The Time is generally within 3s, some high-power components welding time even longer. After welding the first to remove the solder wire, and then the tip and the pin into a 90 ° angle or parallel to the electric iron will be removed. After welding to check whether the welding meet the requirements, try to avoid Weld, short circuit and so on.
2. Chip components welding
(1) welding patch components, such as chip resistors, capacitors, inductive components and diodes, transistors and other devices less pin, the general use of flat oblique knife tip or cone (pointed) tip , The welding is relatively easy.
Patch components of the specific welding process is: you can first add a tin in a pad, and then clamp the components with tweezers on the pad is put on, after welding a pin, and then look at whether the deviation, If it has been put on, then welding on the other pins. In the absence of tweezers can also be the case, with a soldering iron to solder the solder wire in a component on the pin, pinch the solder wire to the components to be welded, with soldering iron soldering device components can be pin. You can also hand the components on the pending welding, with the left hand fingers to suppress the components, and then welding.
(2) if it is solder patch chip
As shown. You can use the tweezers carefully put the chip on the PCB, to ensure that the chip placed in the correct direction, pay attention not to bend, damage the pin, so that the pin and pad alignment. Place the soldering tip with a small amount of solder, press down on the aligned position with your fingers or tool, and solder the pins on the two diagonal positions so that the chip is fixed and can not be moved.
Chip IC welding
After rewriting the diagonal, check the location of the chip is aligned, if necessary, can be adjusted or removed and re-aligned on the PCB positioning.
Apply solder flux evenly to the pin, then solder the tin stack, tilt the board along the direction of the pin to be sold, move the soldering iron downwards from one pin and push the solder to move the pin firmly On the pad.
According to this method to solder the other column pin, if the pin is tin short circuit, with the oblique tip along the radial direction of the pin quickly move, so that the pin can be short-circuit between the tin removed.
If it is difficult to remove these tin, you can add tin to move the soldering iron, or in the tin short circuit plus some flux, will be able to solve the problem. When you have some skilled welding technology, you can operate this, the chip alignment pad, left hand pinch tin line, a small finger or ring finger hold the chip, right hand to take electric iron, first a row of more than a pin tin solder, And then the normal welding.
Note: The purity of the solder wire used here must be high, the tip in the use of the process to keep clean, in the removal of short-circuit pin tin, the tip of the mouth is not the best tin, so as to remove these short-circuit tin. In the same place the number of operations should not be too much to prevent damage to the copper foil, but also note that the dip tip at the pin at the move, the action should be light, not crush the pin and copper foil drag to prevent Blowing a very thin copper foil pad and bend the pin and cause a short circuit. After welding must be carried out after the quality of the welding to check the appearance of solder joints must be consistent with the requirements described above, the conditions permit, the circuit board and then look at the cleaning work is more perfect
3. After cleaning as perfect as new
In the daily production of small and electrical maintenance, the quality of welding on the production and maintenance of a great impact on the quality. Therefore, the study of electronic technology, you must practice welding basic skills, a solid grasp of welding technology.
3. Pin components welding
Some components can be twisted by the tweezers to clamp the components of the device for welding, in a fixed role at the same time, in order to facilitate the components of heat. Common pin components inserted into the PCB in place, by foot welding can be.
Welding multi-foot components, should first solder the two components will be fixed components, if it is chip chip also depends on all the pins have a good correspondence with the pad, and then a pin a pin to weld, Can also be used to weld welding, such as integrated circuit welding can be used drag welding method. In the factory production line are used in this way welding multi-pin components, the specific operation of the PCB is to be on the welding pin into a vertical, and let the PCB and the table surface into a certain degree of slope, and then electric iron contact the most Feet, to be fully heated after the addition of tin, while the electric iron down, kept tin, the use of tin mobility, coupled with the slope of the solder easily flow, the general smooth welding of a series of component pins, if There is a welding and then soldering alone can be. You can also apply some flux at the pin, and then add tin at the top, and then use the soldering iron from top to bottom heating tin to the bottom of the pin on the line.