Soldering circuit version pay attention to those, precautions for circuit board soldering

The soldering iron with temperature control is more convenient to operate, and the tin wire used for soldering is hollow inside, and there is already rosin, so don't add rosin.

Soldering iron head also pays attention to, depending on whether you like the pointed tip or trapezoidal, a lot of related shapes, depending on what component you are soldering, the role is to solder, the soldering iron head should not only use the tip part of the contact, pay attention to the angle, the component is a simple soldering point fixed on the PCB, and then the left hand takes the tin wire close to the part to be soldered, the right hand operates the soldering iron, and the tin part on the soldering iron head starts from the tip 1 3 out of contact tin wire, so the effect is good, without tin tip, it is not easy to appear cold soldering.

After the soldering iron is used, we must pay attention to maintenance, which is very important, that is, after using up, continue to add some solder in the part of the soldering iron head to eat, and turn off the power after evenly melting on it, so that the maintenance will be good when it is used next time.

Soldering should pay attention to, in addition to the angle of the soldering iron tip, as well as the angle of the solder joint on the PCB, the speed of tin wire feeding, different components use different ways, the feel of the good effect will come out, there is a chance to show you :) my hard disk is broken, or I have training materials, I can give you a reference, but unfortunately, it was suddenly hung up, the hard disk.

1. Be sure to clean the circuit board and component pins, the circuit board is gently beaten with fine sandpaper, and the component pins can also be lightly beaten.

2. To solder, it is best to put some rosin on the circuit board and component pins before soldering.

3. When soldering, it is necessary to grasp the temperature and time of the soldering iron, too long time will burn the components, and too short time is easy to solder.

4. It is best to use a good solder wire, and many times bad soldering is often related to the solder wire.

5. You can first suck the tin to the soldering iron and then solder, if you use a solder wire containing rosin, you can also hold the solder wire in one hand and the soldering iron in one hand to solder.

The oxide from the pins of the component is not cleaned, and it is better to hang it a few times with something like a knife;

Then there is whether your solder wire has flux, if not, it can't be soldered;

Finally, there is the temperature, which is to completely melt and fuse the solder before leaving the soldering iron.

Not enough rosin is added, or the temperature is too high.

LZ still needs to buy a soldering iron with temperature control and practice more.

Add some rosin.

And don't weld the copper together.

Beware of electric shocks to the power meter.

Practice brings true knowledge, weld more, watch others weld more! The results will definitely come out.

Add some rosin.

And don't weld the copper together.

1. After getting the bare PCB board, you should first conduct a visual inspection to see if there are problems such as short circuit and open circuit, and then be familiar with the schematic diagram of the development board, and compare the schematic diagram with the PCB silk screen layer to avoid the schematic diagram and the PCB inconsistency.

2. After the materials required for PCB welding are ready, the components should be classified, and all components can be divided into several categories according to the size to facilitate subsequent welding. A complete BOM needs to be printed. In the welding process, if one item is not welded, the corresponding option is crossed out with a pen, so as to facilitate the subsequent welding operation.

Before soldering, anti-finger teasing measures such as wearing an electrostatic ring should be taken to avoid damage to components caused by static electricity. After the equipment required for soldering is ready, the soldering iron tip should be kept clean and tidy. It is recommended to use a soldering iron with a flat angle for the first soldering, which can better contact the pad when soldering components such as 0603 packaging, which is convenient for soldering.

Of course, for the masters, this is not a problem.

3. When selecting components for welding, welding should be carried out in the order of components from low to high and from small to large. In order to avoid the inconvenience of welding smaller components to smaller components. Priority is given to soldering integrated circuit chips.

4. Before soldering the integrated circuit chip, it is necessary to ensure that the chip placement direction is correct. For the chip silk screen layer, generally the rectangular pad indicates the pin at the beginning. When soldering, one pin of the chip should be fixed first, and the diagonal pin of the chip should be fixed after fine-tuning the position of the component, so that the component can be accurately connected to the position and then soldered.

5. There is no positive and negative electrode in the SMD ceramic capacitor and voltage stabilization circuit, and the positive and negative electrodes need to be distinguished between the light-emitting diode, tantalum capacitor and electrolytic capacitor. For capacitor and diode components, the end that is generally clearly marked should be negative.

In the package of SMD LEDs, the direction along the lamp is positive-negative. For the packaged components that are screen-marked as diode circuit diagrams, the negative end of the diode should be placed at one end of the vertical wire.

6. During the soldering process, the PCB design problems found should be recorded in time, such as installation interference, incorrect pad size design, component packaging errors, etc., for subsequent improvement.

7. After the welding is completed, you should use a magnifying glass to check the solder joints and check whether there is virtual welding and short circuit.

8. After the circuit board soldering work is completed, the surface of the circuit board should be cleaned with alcohol and other cleaning agents to prevent the iron filings attached to the surface of the circuit board from short-circuiting the circuit, and at the same time, it can also make the circuit board more clean and beautiful.

1. The length of the arc:

The length of the arc is related to the type of electrode coating and the thickness of the coating. However, short arcs should be taken as much as possible, especially low-hydrogen electrodes. Long arcs can cause stomatosis.

The short arc can avoid harmful gases such as O2 and N2 in the atmosphere from invading the weld metal and forming undesirable impurities such as oxides and affecting the quality of the weld.

2. Welding speed.

The appropriate welding speed is based on the diameter of the welding rod, the type of coating, the welding current, the heat capacity of the welded object, the beginning of the structure and other conditions, and the corresponding changes can not be made.

Maintain the right welding speed, and the slag can cover the molten pool well. All kinds of impurities and gases in the molten pool have sufficient time to float out, so as to avoid the formation of slag inclusions and porosity of the weld. If the speed of the rod is too fast during welding, the shrinkage stress will increase when the welding part is cooled, causing cracks in the weld.