SMT SMD electronic welding tools and welding disassembly skills

SMT electronic factory craft welding is a basic operation technology in the assembly of electronic products, applicable to the trial production of products, small batch production of electronic products, debugging and maintenance of electronic products, as well as some of the occasions that are not suitable for active welding.

It is a soldering iron to heat the metal parts to be welded and tin-lead solder, the metal surface to be heated wet constitute an alloy, in the solder condensation will be welded metal parts connected welding process, so it is also called brazing. By wetting, dispersion, metallurgical bonding three physicochemical processes are completed, the welded parts will not be damaged.

In the craft welding process, there are various specific requirements for welding things and welding materials, which can not be selected at random, resulting in uncontrollable welding process, unqualified products, and hidden quality problems.

In the SMT electronic manufacturing process, it is inevitable that there will be material abnormalities, bad solder, solder paste and other causes of small probability of repair. So, we are in the electronics industry partners whether we know the use of electronic soldering related stuff knowledge and in the SMT patch plus the use of knowledge and desoldering skills have?

SMT SMD in general, remove the processing parts is not so easy. The need for constant practice to grasp, or forced removal is easy to damage the SMT components. Of course, to grasp these techniques need to practice.

SMT SMD processing with soldering dismantling techniques are as follows.

A. Apply to chip components with fewer pins, such as resistors, capacitors, diodes, transistors and so on. First tinned on the PCB between one of the pads, and then the left hand tweezers will be fixed in the mounting position of the components, leaning against the circuit board, the right hand with a soldering iron will be soldered to the pins on the tinned pads. The left hand tweezers can be loosened and the remaining pins can be soldered with tin wire instead. If it is easy to dismantle such parts, just use the soldering iron together to heat the ends of the parts, tin melting and then quietly lift the parts can be.

B. About SMT SMD with more pins of machined components and SMD components with a wider distance, using a similar method. First tinned on the pad, and then the left hand with tweezers to hold the component welding a leg, the remaining leg with the tin wire welding. In general, MOST good use of a hot air gun to take apart these components. One hand holding the hot air gun blowing molten solder, the other hand in the solder melting together with tweezers and other fixtures to remove the components.

C. With regard to components with high pin density, the soldering process is similar, i.e., first solder a pin, and then solder the other pins with the tin wire. The number of pins is large and dense, the alignment of pins and pads is critical. Generally the pads on the corners are plated with small tin. Align the component to the pad with tweezers or by hand, with the edges of the pins aligned. Quietly press the components on the PCB and solder the pins corresponding to the pads with a soldering iron.

MOST ultimately advocate that components with high pin density are mainly removed with a hot air gun, hold the component with tweezers, blow all the pins back and forth with a hot air gun, and then lift the component after it melts. If the need to remove the components, blowing as far as possible not to the center of the components, the time should be as short as possible. After removing the component, use a soldering iron to clean the pad.