How to Choose the Right SMT Reflow Oven

How to choose the reflow soldering size? What temperature zone is more suitable?

Many electronics factories will feel that purchasing a larger reflow soldering can meet the requirements of constant energy, but generally they spend unjust money and sacrifice space. 8 to 10 zone reflow and faster belt speeds may be the best solution in high volume production environments. Our lead-free SMT reflow oven, soldering oven, SMD reflow oven, PCB reflow oven is 6 zone, 8 zone, 10 zone, 12 zone models are our best Best-selling product that excels in handling pick and place throughput, meets reflow specifications for solder paste manufacturers, and provides reliable, high-quality soldering performance.

 

❙  Solder paste heating time

The first thing to consider is the recipe recommended by your solder paste manufacturer for the paste formulation you will use. Solder paste manufacturers typically provide fairly wide window times (in terms of total heating time) for each stage of the reflow profile-preheat and hold time 120 to 240 seconds, reflow time 60 to 120 seconds / time above liquid. We found that an average total heating time of 4 to 4½ minutes (240-270 seconds) is a good, relatively conservative estimate. For this simple calculation, we recommend that you ignore the cooling part of the welded profile. Cooling is important, but usually does not affect soldering quality unless the PCB cools down too quickly.

Heating reflow oven length

The next factor to consider is the total heating time for reflow soldering. Almost all reflow soldering manufacturers provide the heating length for reflow soldering in their specifications, sometimes called the heating tunnel length. In this simple calculation, we only focus on the reflow areas where heating occurs.

 

❙  Transmission speed

For each reflow you are using, divide the heating length (in inches) by the recommended total heating time (in seconds). Then multiply by 60 seconds to get the transmission speed (in inches / minutes). For example, if your solder heating time is 240-270 seconds, and you are considering using a 6-zone reflow with an 80¾-inch tunnel, divide 80.7 inches by 240 and 270 seconds. Multiplying by 60 seconds, this data tells you that you need to set the reflow transmission speed between 17.9 inches and 20.2 inches per minute. Once you have determined the transmission speed you are considering for the reflow, you need to determine the maximum number of boards that can be processed per minute per reflow.

Max reflow plates per minute

 

Assuming you have to load the boards end-to-end on the conveyor of the reflow oven at maximum capacity, it is easy to calculate the maximum output. For example, if your circuit board is 7 inches long and the zone speed of the 6-zone reflow oven ranges from 17.9 inches to 20.2 inches per minute, the maximum throughput of this reflow soldering is 2.6 to 2.9 boards per minute. In other words, the circuit board will be soldered in about 20 seconds.

 

Which reflow oven is best for your needs

Given these factors, there are many other factors to consider. For example, dual-panel production may require both sides of the same component to be reflow soldered, and manual assembly operations will also affect how much reflow soldering capacity is really required. If your SMT assembly is very fast, but other processes limit your plant's output, then the world's largest reflow soldering is not so good for you. Another factor to consider is the transition time from one product to another. How long does it take for the reflow temperature to stabilize when changing from one configuration to another? There are many different things to consider. for more plz contact at smtwhf@163.com

❙  SMT Reflow Oven Video