An article to understand the role and maintenance of reflow soldering machine

The reflow soldering machine is also called a reflow soldering machine or a "reflow oven" (Reflow oven). It provides a heating environment to melt the solder paste, so that the surface mount components and PCB pads can be reliably bonded through the solder paste alloy. Together equipment.

Divided into the development of technology: vapor reflow, infrared reflow, far-infrared reflow, infrared heating wind reflow and full hot air reflow, water-cooled reflow. It is a welding technology developed with the advent of miniaturized electronic products. It is mainly used for the welding of various surface assembled components. This soldering technology solder is solder paste. Pre-apply appropriate and appropriate solder paste on the pads of the circuit board, and place the SMT components in the corresponding positions; the solder paste has a certain viscosity to fix the components; then the components are mounted on the circuit. The board enters the reflow equipment. The transfer system drives the circuit board through various temperature zones set in the device. The solder paste is dried, preheated, melted, wetted, cooled and the components are soldered to the printed board. The core of reflow soldering is the use of an external heat source to heat and melt the solder and reflow it to complete the board soldering process.

A. When the PCB enters the heating zone, the solvents and gases in the solder paste evaporate. At the same time, the flux in the solder paste wets the pads, the terminals of the components, and the pins. The solder paste softens, collapses, and covers the solder. The disk isolates the pads and component pins from the oxygen.

B. When the PCB enters the heat preservation area, the PCB and the components are fully preheated to prevent the PCB from suddenly entering the high temperature soldering area and damaging the PCB and components.

C. When the PCB enters the soldering zone, the temperature rapidly rises to bring the solder paste to a molten state. The liquid solder wets, diffuses, diffuses, or reflows the PCB pad, component tips, and leads to form a solder joint.

D.PCB into the cooling zone, so that the solder joints are solidified; reflow is completed.

Reflow technology is not unfamiliar in the electronic manufacturing domain. The components on the various boards used in our computers are soldered to the board through this process. The advantage of this process is that the temperature is easy to control, oxidation can be avoided during the welding process, and manufacturing costs are also easier to control. Inside the device there is a heating circuit that heats the nitrogen to a sufficiently high temperature and blows it to the circuit board on which the component has been mounted so that the solder on both sides of the device melts and bonds to the motherboard.

1. To set a reasonable reflow temperature curve and perform real-time testing of the temperature curve on a regular basis.

2. Solder according to the soldering direction of the PCB design.

3. Prevent belt vibration during welding.

4. The soldering effect of the block printed board must be checked.

5. Whether the welding is sufficient, whether the surface of the solder joint is smooth, whether the shape of the solder joint is in the shape of a half moon, the condition of the solder ball and the residue, the condition of the continuous soldering and the dummy soldering. Also check the PCB surface color changes and other conditions. And adjust the temperature curve according to the inspection result. The welding quality must be checked regularly during the entire batch process.

Surface-mounted boards for reflow soldering process are more complex and can be divided into two types: single-sided mounting and double-sided mounting.

A, single-sided placement: pre-painted solder paste → patch (divided into manual placement and machine automatic placement) → reflow → inspection and electrical test.

B, double-sided placement: A surface pre-painted solder paste → patch (divided into manual placement and machine automatic placement) → reflow → B surface pre-painted solder paste → patch (divided into manual placement and machine automatic Mounting) → reflow → inspection and electrical test.

The simple process of reflow soldering is "silk screen solder paste--patch--reflow soldering, the core of which is the accuracy of silk screen printing, the fixed-rate of the patch is determined by the PPM of the machine, and the reflow is to control the temperature rise and high temperature. And descending temperature curve."

The reflow soldering machine is a device that reliably fuses surface-mount components and PCB pads with solder paste alloys by providing a heated environment to melt the solder paste. Divided into the development of technology: vapor reflow, infrared reflow, far-infrared reflow, infrared heating wind reflow and full hot air reflow, water-cooled reflow. It is a connection technology developed with the advent of miniaturized electronic products. It is mainly applied to the welding of various surface assembled components. This soldering technology solder is solder paste. Pre-apply proper and appropriate solder paste on circuit board pads, place the SMT component in the appropriate position, fix the solder paste to fix the component, and then place the component on the circuit. The board enters the reflow equipment. The transfer system drives the circuit board through various temperature zones set in the device. The solder paste is dried, preheated, melted, wetted, cooled and the components are soldered to the printed board. The core of reflow soldering is the use of an external heat source to heat and melt the solder and reflow it to complete the board soldering process. According to the PCB board in different links, each link plays a different role.

1, the role of warming area

The temperature rising zone is in the first stage of reflow soldering. It preheats and heats the PCB board, activates the solder paste, evaporates part of the solvent, and evaporates the moisture of the PCB board and components to eliminate the PCB board. Stress.

2, the role of heat preservation area

The PCB board enters the heat preservation area, reaches a certain temperature, prevents from suddenly entering the welding high temperature area, damages the PCB board and the component. The function of this temperature zone is also to keep the temperature of the components stable, to keep the temperature of components of different sizes on the PCB all the time, to reduce the temperature difference of the entire PCB, and to volatilize the flux in the solder paste to remove the pads. Oxides of components and pins.

3, the role of welding area

PCB board into the welding area, the highest temperature, then paste from the paste has become liquid-like, fully infiltrated pad, component pins, the duration of this link is relatively short, to prevent damage to the PCB board and components at high temperatures.

4, the role of cooling area

After the solder paste becomes a liquid, it can be cooled down. The faster the cooling rate, the better. The cooling rate is too slow, and it is easy to produce rough gray. Generally, it cools down to 75° C. and it cures. Then the PCB board is realized. Soldered.

The daily insurance is carried out on-duty by the equipment-operating workers, and the four things in the class, the attention in the class, and the four things in the class are seriously performed.

(1) Four things in the class to digest the pattern data and check the shift record. Wipe equipment and lubricate as required. Check whether the handle position and manual operation position are correct and flexible, and whether the safety device is reliable. Low speed operation Check if the drive is normal, lubrication, cooling is

No flow.

(2) During the class five pay attention to the operating sound, temperature, pressure, liquid level, electrical, hydraulic, pneumatic system, instrument signals, and safety insurance.

(3) Close the switch after four things in the class and put all the handles to zero. Remove iron scraps and dirt, clean the oil on the track surface and sliding surface of the equipment, and add oil. Clean the workplace, organize attachments and tools. Fill in the shift record and operating time record, and handle the shift procedures.

Zhou Baobao is operated by the equipment operator every weekend. The maintenance time is: General equipment 2h, fine, large, thin equipment 4h.

(1) Appearance Clean the equipment rails, transmission parts and exposed parts, clean the work site. To achieve cleanliness and corrosion inside and outside, rust, clean surroundings.

(2) Manipulation drive Check the technical condition of each part, tighten the loose parts, and adjust the fit clearance. Check interlocks and safety devices. The transmission sound is normal, safe and reliable.

(3) Hydraulic lubrication oil line, dust felt, oil filter, oil added or oil change. Check the hydraulic system to achieve oily cleaning, oil flow, leakage, and grinding.

(4) The electrical system wipes the surface of the motor and snake skin, inspects the edges, and is grounded to achieve integrity, cleanliness, and reliability.

(1) Clean the machine to widen the screw and add high-temperature oil

(2) Clean the interior of the reflow oven

(3) Check whether each heating motor is operating normally

(4) Clean heating wind wheel

(5) Cleaning the upper/lower rectifying orifice

(6) Test the temperature difference of the machine and record

(7) Clean the exhaust fans

(8) Cleaning and Recovery Rosin System Device

(9) Replace the water in the purging machine

(10) Apply high temperature oil to each contact high temperature circuit

(11) Check the machine emergency stop device (safety)

(1) Check for vibrations and noises in the transportation process and notify the reflow machine repair if necessary.

(2) Check that the shipping motor's fixing screw is loose, and if it is loose, lock the screw.

(3) Check if the tension of the drive chain is appropriate. If necessary, adjust the motor positioning screw in time.

(4) Check that there are coke and black powder on the transport chain. If any, clean it with diesel immediately.

(5) Check the width of the movable end of the track to adjust the synchronization axis positioning, whether the fixed block is loose, if any loose should be locked in time.

(6) Check if the hot air motor positioning screws are loose, and lock them in time if loose.

(7) Check the dust and foreign matter in the control box of the electrical system. If there is any foreign matter, the dust and foreign matter should be blown out with the same pressure air.

1. In order to ensure personal safety, the operator must remove the labels and ornaments and the sleeves should not be too loose.

2. Pay attention to high temperature during operation to avoid scald maintenance

3 can not be set free reflow temperature and speed

4. Ensure that the room is ventilated. The exhaust pipe should lead to the outside of the window.

Bluetooth Speakers

Wireless Speaker,Bluetooth Speakers,Bt Wireless Speaker,Portable Bluetooth Speaker

Guangzhou YISON Electron Technology Co., Limited , https://www.yisonearphone.com