Soldering is one of the most essential skills required to enter the electronics world for many electronics enthusiasts. In fact, soldering is the only perpetual way to connect components to a circuit. PCB soldering, to some extent, will bring you find out the simplest shortcut to open up the universe of electronics.

Overview of PCB Soldering Tactic

After getting the PCB bare board, you should  carry out a through appearance inspection to see if there is a short circuit, open circuit and other issues. Then be familiar with the development of the schematic diagram of board and compare the schematic with the PCB printing layer to avoid the incompatibility between schematic and PCB.

Prepare the PCB soldering materials required. The components should be classified according to the size of all components and divide them into several categories to facilitate subsequent soldering. 

Before soldering, you should wear electrostatic rings and other anti-static measures to avoid electrostatic damage to components. Ensure the soldering equipment required such as the head of the soldering iron clean and tidy. 

The selection of components for PCB soldering should be in accordance with the components order from low to high, from small to large. Unless you’re working with an exceptionally simple circuit board, you’ll likely only be soldering one or two components at once, as opposed to doing the entire board in one session. We recommend starting with the smaller pieces and working up to the larger ones. This helps keep the board flat and balanced as the process begins, rather than weighing it down on one side with a single heavy piece.

Begin by selecting a few small components and placing them where they belong on the board. Bend the leads as you find you need to and insert the component into the holes where they belong. If you’re having trouble getting the piece to stay still once you aren’t holding it in place, try bending the leads so that they rest at a 45-degree angle along the bottom of the board.

For the soldering of plug-in components, such as power module related with components, the device can be modified after the pins before soldering. After the components are placed and fixed, generally in the back through the soldering iron will be melted after the solder from the pad into the front. Do not have to put too much to solder, but first of all, you should make the components stable.

Promptly record the soldering process during which you find the PCB design problems, such as installation interference, incorrect design of pad size, component packaging errors, etc., so that you can prepare for subsequent improvements. If you have a soldering microscope, that will much convient. With a soldering microscope, you can not only record video of the soldering process but also improve the precision of soldering. 

Tips on Soldering 

1.Selection of Good Soldering Iron:
Selection of the Soldering Iron is very important. Soldering Iron is the electric device that heats the solder lead and makes the joint. Many types of soldering irons are available, so select one with 15-25 watts. If the wattage of the Iron is too high, it may destroy the heat-sensitive components or causes detachment of PCB tracks. Choose the Iron with a 3 pin cord. The earth connection is important to remove the stray current that accumulates in the iron tip. This is very important while soldering static-sensitive components like CMOS ICs and MOSFETs.

2.Use the Better Soldering Wire:
Solder lead joins the component leads with the PCB contacts firmly. The quality of the solder lead should be good enough to, make the soldering process perfect. Rosin core solder is a good choice. Do not use the Acid core solder used to solder electrical contacts and plumbing metal joints since the acid content will corrode the copper tracks of the PCB. Good solder contains 60% Tin and 40% Lead. Solder with 0.75 to 1mm diameter is good. Some makes of solder contain a core of flux inside.

3.Use Little Soldering Flux
Soldering flux is usually applied to the solder joints before soldering. The flux reduces the melting point of the lead so that the solder lead will melt easily and spread uniformly on the solder joint. Liquid type flux is better since it will not leave dirt after soldering. Fumes from the flux are toxic so do the soldering work in a well-ventilated place and use an exhaust fan in the room.

4.A well-maintained Tip can make the soldering easy
Good soldering requires a clean soldering iron tip. If the soldering Iron is a newly purchased one, first apply a layer of lead before starting the soldering. This is called Tinning which will helps to transfer heat easily. After prolonged use, the tip will become dirty which will make the soldering process difficult. So before starting the soldering, clean the tip using a File or Sandpaper and make it glowing. After cleaning, wipe the tip with moist cotton or sponge. Since the soldering process is intermittent, keep the soldering iron tip on a heat sink. An old porcelain fuse carrier can be used for this or purchase one soldering iron stand with a heat sink.

Read More:

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