Category Archives: Reflow soldering

Vacuum Reflow oven S-V8000

Vacuum Reflow oven S-V8000

Applications: IGBT packaging, LED eutectic, solder paste process, high clean soldering process, laser diode package, hybrid integrated circuit package, package cover package, MEMS and vacuum package.
Industry application: S-V series vacuum reflow soldering machine is an ideal choice for R&D, process research and development, high-capacity production, and is the best choice for high-end R&D and production in military enterprises, research institutes, universities, aerospace and other fields.The product weld void rate is as low as 3% or less.

Features:

It adopts imported heating parts, uniform temperature and high thermal compensation efficiency. It is suitable for CSP, BGA, automobile lamp, UV lamp, LED flip chip process, laser device package, IGBT power device package process soldering;

Special wind wheel design, large air exchange and stable wind speed;

Each temperature zone adopts forced independent circulation, independent PID control, and independent heating mode to make the furnace cavity temperature accurate and uniform, and the heat capacity is large:
4, the temperature rises quickly, from room temperature to working temperature ≦ 30 minutes;

Imported high-quality high-temperature high-speed motor has stable wind, low vibration and low noise;

The furnace body adopts double cylinder (electric push rod) jacking device, which is safe and reliable;
7, chain, mesh belt synchronous constant speed transportation, using frequency conversion precision high speed;
8, special high-quality aluminum alloy rail design, small deformation, chain automatic refueling device;
9, UPS power-off protection function, to ensure the normal output of the PCB after power-off, not damaged;

Powerful software function, monitor and measure the temperature of the PCB board online, and analyze, store and print the data curve at any time;
11, industrial control PC and PLC communication using MODBUS protocol, work stable, to prevent the phenomenon of crash;
12, automatic monitoring, display equipment working status, you can make correction parameters at any time;

Special patented furnace design, good thermal insulation, and the lowest power consumption in the same industry;

The patented guide rail is not deformed at high temperature, and the three-wire rod synchronously widens the structure, effectively ensuring that the guide rails are parallel, preventing the board from falling, the occurrence of the card board, no cleaning, and easy adjustment. The adjustment operation can be performed both automatically and manually.

Standard chain and net chain synchronous iso-speed parallel transportation, can process single-sided and double-sided PCB boards, and optional double-rail transportation system.

The automatic width adjustment system adopts closed-loop PID control, which can be automatically adjusted to the required width according to the parameters input by the computer, and the accuracy can reach 0.2mm.

Due to the modular design of each temperature zone, hot air motor and heating wire are convenient for maintenance and repair.
18, strong cooling air cooling, cold air exchange fast, uniform wind speed, slope can be controlled by frequency conversion, tin point is smooth and bright;

The nitrogen flow meter can monitor the nitrogen flow at any time;
20, in the traditional SMT welding process, to improve, reduce the voids in the solder, the void rate can reach less than 5%;
21, high-quality products for mass production, the shortest product welding process cycle is 30S, to maintain continuous production;

At the same time, the equipment meets the traditional SMT process production configuration, nitrogen welding process and air welding process;

The vacuum part is independently controlled, and can be configured according to the process of the product, or can be shielded with the traditional process product to close this function;

Model S-V8000
Heating part parameters
Number of pre-zones 8/8
Heating zone length  3000mm
number of cooling zones 2/2
Vacuum zone
Number of vacuum zones 1
Product size  smallest size:100*100MM;biggest size:300*350MM, 
vacuum 10-100pa
Vacuum pumping speed 40m³/h  Adjustable
Visual observation window 1
Heating system (optional) Space maximum temperature 350 degrees
Flux recovery system Reduces equipment maintenance and increases component life
System Control Touch Screen + Siemens PLC
Process control action Vacuuming time, vacuum pressure, vacuum pumping speed, vacuum maintenance time, deflation time free control setting
Transmission part parameters
Mesh belt width  500MM

Transport rail adjustment range  50-450MM
Transmission direction L-R(R-L)
Transportation height  900±20MM
Transmission mode  mesh belt + chain transmission
Transmission speed 300-2000mm/min
power supply Three five-line 380V 50/60HZ
Starting power 52KW
Normal work consumption Approx Approx.10KW
Heating time 20min
Temperature control range Room temperature -350 degrees
Temperature control  Full computer PID closed loop control, SSR drive
Machine control mode PC+PLC
Temperature control accuracy ±1
PCB board temperature distribution difference ±1-2
Cooling method Cold water cooling
Alarm temperature     Abnormal temperature (super high temperature or ultra low temperature after constant temperature)
Tricolor light indication Three-color signal indicator: yellow – warming green – constant temperature red – abnormal
Weight Approx.2800kg
Dimensions L5650*W1400*H1600
Exhaust requirements   110 cubic / min   2 channels φ180mm
Nitrogen protection device Nitrogen flow rate 20-30 cubic meters / hour oxygen concentration 500-800PPM
External water cooling system Power 3P cooling speed ≥6 degrees / sec

DIP, PCB Assembly,Chip Mounter, Pick and Place, IC Mounter, High Speed Mounter, Wave soldering,LED lighting, LED Lamp, LED Display, LED tube,UPS, Power Converter, Power Adepter, Mobile Charger, PCB board handling system, Loader, Unloader, Conveyor,Shuttle, Chip Mounter, Pick and Place, IC Mounter, High Speed Mounter Induction Cooker, AC, Electric Cooker, Fan, TV, Settle Box

Reflow oven technology and precautions

Reflow oven technology and precautions

Far infrared reflow again

In 80s the use of far infrared reflow has the characteristics of fast heating, energy saving, stable operation, but because the printed circuit board and various components for different material, color and thermal radiation absorption rate to have very big difference, caused by a variety of different components and different parts of the circuit temperature is not uniform, the local temperature difference. For example, the black plastic package of integrated circuit will be overheated due to the high radiant absorption rate, and the welding part of it will lead to false welding on the silver lead instead of low temperature. In addition, the heat radiation blocked on printed boards, such as welding pins or small components in the shadow parts of big (high) components, will cause poor welding due to insufficient heating.

1.2 full hot air reflow again

Full hot air reflow oven  is a welding method by which the flow of airflow is forced through a convective nozzle or a heat-resistant fan, so that the welded parts are heated. This kind of equipment began to rise in 90s. Due to the adoption of this heating mode, the temperature of PCB and components is close to the temperature of the given heating area, which completely overcomes the temperature difference and shadowing effect of infrared reflow soldering, so it is widely applied now. In all hot air reflow oven  equipment, the convection velocity of the circulating gas is very important. In order to ensure that the circulating gas acts on any area of the printed board, the air flow must have a fast enough speed. To a certain extent, it is easy to cause the jitter of the printed board and the displacement of the components. In addition, in terms of heat exchange, the efficiency is poor and the power consumption is more.

1.3 infrared hot air reflow again

This kind of reflow oven is a more ideal heating method, which is based on the IR oven with hot air to make the temperature even more uniform insaide the oven. The characteristics of this kind of equipment to make full use of the infrared penetration, high thermal efficiency, energy saving, and effectively overcome the temperature difference of infrared reflow soldering and shadowing effect, and make up the influence of hot air reflow on gas flow caused by excessive demand, therefore  at international this kind of IR+Hot reflow is used most commonly  at present .

With the increase of assembly density and the appearance of fine spacing assembly technology, a reflow oven  furnace with nitrogen protection has appeared. Welding under nitrogen protection conditions can prevent oxidation, improve welding wetting power and speed up wetting speed. It is more suitable for uncleaning process to reduce the welding force and reduce welding beads.

2  The establishment of  temperature curve

The temperature curve is the curve of the temperature of a point on the SMA will change over time when SMA through the reflow oven. The temperature curve provides an intuitive method to analyze the temperature change of a component during the whole reflow process. This is very useful for obtaining the best weldability, avoiding damage to the components due to overheating, and ensuring the quality of the welding.

The following is a brief analysis of the preheating section.

2.1 preheating section

The purpose of this section is to put PCB at room temperature as soon as possible heating, to achieve second specific targets, but the heating rate should be controlled in the appropriate range, if excessive, will produce thermal shock, circuit boards and components may be damaged; if too slow, will not fully solvent, affecting the welding quality. Due to the rapid heating rate, the temperature difference in the rear section of the temperature zone is larger than that in the SMA. In order to prevent the damage of thermal shock to the component, the maximum speed is 4℃/s. However, the normal rise rate is set to 1-3℃/s. The typical heating rate is 2℃/s.

2.2 heat preservation section

The heat preservation section is the area where the temperature rises from 120℃-150℃ to the melting point of the solder paste. Its main purpose is to make the temperature of each element in the SMA stable and minimize the temperature difference.In this area, the temperature of the larger components can have enough time to catch up with the smaller components and ensure that the flux in the solder paste is fully volatile. The oxide of the soldering plate, the solder ball and the pin of the element is removed, and the temperature of the entire circuit board is balanced until the end of heat preservation section. It should be noted that all elements on the SMA should have the same temperature at the end of heat preservation section, otherwise, entering the reflux section will cause various bad welding phenomena due to the uneven temperature of each part.

2.3 reflow  section

In this area, the temperature of the heater is set to the highest, which makes the temperature of the component up to the peak temperature. In reflow sectionthe,the different of peak temperature is according to the solder paste to change, the general recommendation for solder melting point temperature plus 20-40℃. For 63Sn/37Pb solder paste with melting point of 183℃ and Sn62/Pb36/Ag2 solder paste with melting point of 179℃, the peak temperature is generally 210-230℃. Reflow time should not be too long to prevent adverse effects on SMA. The ideal temperature curve is the smallest area covered by the “tip zone” of the solder melting point.