What to look at for the soldering mask of the circuit board, and the precautions for the soldering o

Xin Jinhui will answer for you, the circuit board solder mask needs to see the 17 steps of detection.

1. Whether the color of the solder mask is consistent with the sample.

2. Whether there is copper exposure.

3. Whether there is scratching.

4. Whether there is uneven ink, ink covering lines, etc.

5. Whether there are air bubbles.

6. Whether the repair is poor.

7. Whether there are white spots and white spots.

8. Whether there is sandwich separation.

9. Whether the overall dimensions are consistent with the sample.

10. Whether the plate bend and plate warp meet the requirements.

11. Whether the amount of tin eaten meets the requirements.

12. Whether the V-cut meets the requirements.

13. Whether the characters are clearly visible.

14. Whether the characters are consistent with the sample.

15. Whether the line meets the requirements.

16. Whether the pad meets the requirements.

17. Whether the drilling meets the requirements.

The PCB circuit board soldering mask process is one of the key steps in the PCB production process that is easy to affect the quality, so the production management process is strict, and the requirements for personnel work experience and professional ability are high.

The main thing is to see whether the solder mask is qualified, whether there are quality defects, and whether the color and thickness of the ink used meet the requirements of customers;

However, there are many defects in the printing process, so after printing, it is necessary to see whether the solder mask layer is uniform, whether there are impurities, and whether the thickness is appropriate. After passing the qualification, the post-process can be released.

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.

Anti-static measures such as wearing electrostatic rings should be taken before welding 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, they should be welded 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.

Circuit board DXT-V8 repair solder wire Insert components pay attention to the positive and negative poles Pay attention to the soldering angle when soldering.

Static electricity generated by short circuits and soldering irons.

Pay attention to anti-static, the soldering iron is grounded, and pay attention to the smooth and full solder joints of virtual soldering, continuous welding and false soldering.

The words of solder-mask class and station are all words of Taiwanese circuit board companies. The main route road slab factory is called the solder mask process and type of work.

The solder mask process is the most difficult process in the circuit board, and there are many types of work in this process, such as solder mask screen printers, ** staff, aligners, screen makers, ink debugging personnel, as well as inspectors, technicians, etc.

The production efficiency of the solder mask process determines the production efficiency of a PCB factory, so this process is more important.

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.

Before the wire is welded, the insulating sheath should be stripped off, and then the above two treatments can be formally welded. If it is a wire with multiple strands, it should be screwed together after polishing and then tinned.

The names of circuit boards are: circuit boards, PCB boards, aluminum substrates, high-frequency boards, thick copper plates, impedance boards, PCBs, ultra-thin circuit boards, ultra-thin circuit boards, printed (copper etching technology) circuit boards, etc. 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.

The circuit board can be called a printed circuit board or a printed circuit board, and the English name is (Printed Circuit Board) PCB, (Flexible Printed Circuit Board) FPC Circuit Board[1] (FPC circuit board, also known as flexible circuit board, flexible circuit board is a kind of flexible printed circuit board made of polyimide or polyester film as the substrate with high reliability and excellent excellence. It has the characteristics of high wiring density, light weight, thin thickness and good bendability! ) and Soft and Hard Combination Plate (Reechas) - The birth and development of FPC and PCB has given birth to the new product of Rigid-Flex Board.

Therefore, the rigid-flex board is a flexible circuit board and a rigid circuit board, which are combined together according to the relevant process requirements after pressing and other processes to form a circuit board with FPC characteristics and PCB characteristics.

It's better to have someone teach you and practice it yourself so that it comes quickly. And sum up the experience.

If it is manual welding, both methods can be used, first weld and then shear: the excess line should be folded along the line plate mouth at an angle of about 45 degrees, and the direction of bending is best in the same direction for the convenience of welding, and the soldering iron tip should be properly ground into a concave small groove with a slightly wider line, and cut with diagonal pliers after welding; Shear first and then weld: but after shearing some components are easy to loosen and fall, there is nothing special when soldering, no matter how soldering, the soldering iron must be crisp when leaving the solder joint, but the temperature of the soldering iron, the flux is also very critical, in short, it takes more tests to weld a good point.

1. The circuit board should be clean, preferably tinplated.

2. If the component is a new component, do not deal with it, the pin has solder, and it can be soldered directly.

3. The electric soldering iron should be tinned first to facilitate heat transfer.

4. After the component is perforated, first put the soldering iron close to the pin, the solder wire touches the shiny part of the soldering iron, and after melting, move the solder wire around the pad.

5. When the solder is enough, take away the solder wire.

6. The soldering iron should be left for 1 3 seconds to complete the metallurgical process.

There is a thing that is specially used as a high-temperature protection during welding, called solder mask, also called solder mask. That is to say, when performing high-temperature soldering, reflow soldering, and wave soldering, for the places that need to be protected, such as PCB, vias, contacts, stylus, satins, and gold fingers, etc., a primary solder mask film (solder mask) can provide short-term high-temperature protection during soldering and protect them from high-temperature damage. It is also very easy to remove after welding, and can be torn off directly or rinsed with water.

Mud went to the master who repaired the TV set, there was a soldering machine, and most of the originals on the PCB board were soldered.

The circuit board is to be soldered.

1. Usually only one side is welded, and the other side is the component surface, no welding.

2.The solder protrudes from the board in millimeters. Depending on the size of the pad, the solder height is usually measured from the radius to the diameter of the pad.

3.Tin fills the holes throughout the board. Generally, if the requirements are not high, visually welded, and then drag the components by hand, and you can't pull them off. If the reliability requirements are high, the solder must be full and rounded, and the holes should naturally be filled.

This is not difficult:

If you don't want to ask your parents for help, go to the hardware store outside, repair home appliance stores, repair mobile phones and other electronic products stores, and find employees or bosses inside to help (or negotiate a price with him, this should be very cheap, it should not exceed 5 yuan) under your brazing, which kind of soft tin wire is used to melt the electronic components and circuit boards together.

If you can ask your parents for help, then talk to them and ask them to find some tin wire at home, or buy some and come back and use a special soldering iron (or find a way) to melt the tin wire for you.