How to solder the circuit board, how to solder the circuit board, how to solder the circuit board

How to solder the circuit board, first adjust the computer iron to 350 degrees 10 degrees, and then make an appointment for 2 3 seconds on the head of the computer iron, and then put the solder wire at the head of the computer, which is the solder line melted and the solder fully understands the impact of the pad and software for 1 2 seconds, and the soldering iron is completed.

In our country, welding operations need to be licensed, welders are the type of work that belongs to the access category, in the professional qualifications of skilled personnel, only five of the 81 types of work in the access category, welders are one of them, and the actual situation is that most of the industry practitioners are unlicensed operations. With the continuous standardization of technology and the relevant requirements of the industry, more and more people want to take a welding certificate, the advantage of the certificate is still very large, first of all, the salary of the certificate and the non-certificate are very different, often able to reach more than double or higher level. Therefore, the issue of short-term welder training has naturally become a concern for practitioners.

Welding as an industrial "tailor" is a very important means of processing in industrial production, the quality of welding plays a decisive role in the quality of the product, so, what is the future development of welding technology?

Industry outlook. With the development of production, welding is widely used in aerospace, aviation, nuclear industry, shipbuilding, construction and machinery manufacturing and other industrial sectors, in China's economic development, welding technology is an indispensable means of processing. After entering the 21st century, welding is an important part of the manufacturing industry, and the rapid development, so it has brought unprecedented development opportunities to the welding industry.

At present, China consumes 300 million tons of steel every year (about tons of welded structure), and needs about 750,000 welding machines, and the welding industry will continue to grow in the next 8 10 years.

The circuit board soldering methods and skills are as follows:

Sit upright, hold the solder wire in the left hand, hold (grasp) the soldering iron in the right hand, and hold the soldering iron with eyes about 30cm from the solder point and below 50w in a pen-holding position, and use a grasping holding position for the soldering iron above 50w; The angle between the tip of the soldering iron tip and the circuit board is generally between 35°-55°.

After the soldering iron is heated, first put the soldering iron tip on the weldment to heat it a little and then put the solder wire in an appropriate amount, the time interval between the soldering iron and the tin wire is 1-3 (seconds), the specific situation depends on experience, it can be said that practice makes perfect; The amount of solder can not be too much, otherwise there will be too much swelling, or even leakage to the opposite side and cause a short circuit of adjacent solder joints, less is lacking full, and the general amount of solder is 90-120% of the volume of the soldered hole.

When soldering, it should be heated evenly, that is, the soldering iron heats the pin and pad at the same time, gently pinch the wire solder with the thumb and index finger, and generally leave 2-5cm of tin wire at the end, and push it forward with the help of the middle finger. When soldering, the side of the tip of the soldering iron and the side of the tente of the element are moderately rubbed with light force to produce a rough surface of friction, so that it can fully dissolve the tin.

When cutting the pins, the circuit board should be oblique to the ground, try to make the pins fall on the floor or in the waste box, and generally leave the solder joints in the appropriate, except for the yuan required to cut the feet. After the soldering is completed, the components and the circuit board should be well connected, and undesirable phenomena such as virtual soldering and desoldering are never allowed, and the solder overlay rate of each solder joint is more than 80%.

Circuit boards

The circuit board makes the circuit miniaturized and intuitive, and plays an important role in the mass production of fixed circuits and the optimization of the layout of electrical appliances. A circuit board can be referred to as a printed circuit board or a printed circuit board.

Welding is a method of making metals joined. It uses heating means to form a permanent firm bond between the two metals at the contact surface of the two metals through the mutual diffusion of atoms or molecules of the welding material, and the contact formed by the connection by welding method is called a solder joint. It takes 2 3s to complete the two processes of wetting and diffusion, and only 35% of the two processes of wetting and diffusion are completed in 1s.

Generally, the welding time of IC and transistor is less than 3s, and the welding time of other components is 4 5s. Flux must also be pre-applied prior to soldering, as opposed to wave soldering, where the flux is only applied to the lower part of the board to be soldered, not the entire PCB.

In addition, selective soldering is only applicable to the welding of cartridge components, selective soldering is a completely new method, and a thorough understanding of selective soldering processes and equipment is necessary for successful soldering.

1. Preparation. Prepare the solder wire and soldering iron. At this time, it is particularly emphasized that the head of the soldering iron should be kept clean, and the soldering iron should be tin before use, and the specific method is:

Heat the soldering iron, and when the solder can just be melted, evenly coat the soldering iron tip with soldering iron, so that the soldering iron tip eats a layer of tin evenly.

2. Heating weldments.

Touch the soldering iron to the soldering point, pay attention to the first to keep the soldering iron heating all parts of the weldment, such as the lead and the pad on the printed board to make it heated, and then pay attention to let the flat part of the soldering iron tip (larger part) contact the weldment with a larger heat capacity, and the side or edge part of the soldering iron tip to contact the weldment with a small heat capacity, so as to keep the weldment evenly heated TSDQGYSC-003. When soldering, the soldering iron tip is at a 45° angle to the PCB board, and the electric soldering iron tip is pressed against the pad and component pins, and then the component pins and pads are evenly preheated.

3. Melt the solder.

When the weldment is heated to a temperature that melts the solder, the wire is placed in the solder joint, and the solder begins to melt and wet the solder joint. The solder joints should be in the shape of a sine crest, the surface should be bright and smooth, with tin-free thorns and a moderate amount of tin. The feeding angle of the solder wire is about 30°, and the soldering iron tip is kept immobile until the solder melts smoothly and penetrates into the solder joint, so that the solder joint is cooled and solidified in a natural cooling way, and cannot be touched before condensation.

4. Remove the solder.

When a certain amount of solder has been melted, the solder wire is removed.

5. Remove the soldering iron.

When the solder is completely wetted and the soldering iron is removed, take care to remove the soldering iron in a direction that is roughly 45. After the solder wire is removed, the soldering iron continues to be placed on the pad for 1 3 seconds, when the solder only has a slight smoke coming out, you can take away the soldering iron, when taking away the soldering iron, do not pick up too quickly or forcefully, so as not to splash off the solder beads, tin spots, or make the solder point sharp, etc., at the same time to ensure that the soldered components do not move or be shocked before the solder solidifies, otherwise it is easy to cause loose solder joint structure, virtual soldering and other phenomena.

Welding is divided into three categories, pressure welding, fusion welding, and brazing. The circuit board belongs to the brazing inside the soldering iron brazing. An electric soldering iron is a basic tool for manual soldering, and its role is to transfer the appropriate amount of heat.

It is sent to the soldering site so that the solder can be melted without melting the component, so that the solder is connected to the metal being soldered.

Connect.

There are generally two methods for circuit board DXT 398A soldering, one is manual soldering and the other is wave soldering, and the shipment volume of manual soldering is slightly slower.

For electronics enthusiasts amateur production of some circuit boards, can only solder by hand, soldering one or two pieces is generally no problem, but occasionally to solder a dozen pieces, it may not be so good state, want to solder well must first understand the circuit board soldering skills, let me briefly introduce the circuit board soldering skills.

Step 1 of board soldering tips.

First of all, heat the soldering iron, burn it until it is just enough to melt the solder, apply the flux, and then evenly spread the solder on the soldering iron head of Antaixin electric soldering iron, and form a thin and bright layer of tin on the surface of the soldering iron tip.

Secondly, when carrying out more general soldering, one hand holds the soldering iron, the other hand holds the solder wire, close to each other, and the soldering iron tip is close to the root of the solder wire and touches it lightly to form a solder joint.

Then, in the welding process, the welding time should not be too long, if the welding time is too long, it is easy to burn the welding components, and auxiliary tools can be used if necessary. Finally, the soldering iron should be placed on the soldering iron holder.

Step 2 of the board soldering technique.

The welding sequence of the components should be carried out in the order of first difficult and then easy, first low and then high, first patch and then insertion. For example, the pin-dense integrated chip is the most difficult place in the soldering process, and if the soldering difficulty is put at the end, in case there is a defect in the soldering, resulting in damage to the pads, then all the previous efforts will be in vain. Therefore, the order of the first difficult and then the easy is still very practical.

As for why it is low first and then high, it is because it is more convenient when welding. If there are many tall components in the circuit, it will be inconvenient to solder the components with a lower height if the components with a higher height are soldered first. If the insertion component is soldered first and then the chip is mounted, the circuit board will be unevenly placed on the soldering table during soldering, resulting in soldering defects.

About circuit board soldering tips.