Reflow Soldering Oven /Nitrogen Reflow Soldering

SMT Nitrogen Reflow Soldering Oven Overview

Nitrogen reflow soldering is a soldering process in which the SMT (Surface Mount Technology) reflow chamber is filled with nitrogen gas. Its main purpose is to prevent oxidation of component feet during the soldering process and to enhance solder quality. Nitrogen reflow soldering is usually carried out in an environment with a very low oxygen content (100PPM) or less, which avoids the problem of component oxidation.

Advantages of Nitrogen reflow soldering:

1. Prevent the reduction of oxidation: Nitrogen is an inert gas, not easy to have a chemical reaction with the metal, so it can effectively isolate the oxygen in the air in contact with the electronic components to reduce the oxidation phenomenon.

2. Improve solder wettability: In a weak oxygen environment, the tension on the surface of the solder will be less than in a normal oxygen environment, which can effectively improve the fluidity and wettability of the solder.

3. Reduce the generation of solder balls: Nitrogen reflow soldering can avoid bridging, so as to get better solder quality.

4. Improvement of solder joint performance: The use of nitrogen reflow can reduce the discolouration of the substrate, but also the use of lower active flux paste, which helps to improve the performance of the solder joint.

Disadvantages of Nitrogen Reflow Soldering Oven:

1. Increased Costs: The main issue with Nitrogen Reflow Soldering Oven is to ensure that the oxygen content is as low as possible, but this can lead to a significant increase in cost, which increases with the amount of Nitrogen.

2. Possible increase in the chance of "monumentation" of small RLC sizes: The characteristics of nitrogen may lead to a difference in the wetting time of the electrodes at the two ends of the part, which ultimately creates a "monumental" effect.

3. Potential Short Circuit Bridging due to "Capillarity": Nitrogen reflow may lead to an increased "capillarity" effect, which may lead to an increase in the part's tin crawl height, thus increasing the potential for short circuit bridging.

Comparison between Nitrogen Reflow Soldering Oven and Vacuum Reflow Soldering Oven

Nitrogen Reflow Soldering Oven is second only to Vacuum Reflow Soldering Oven, and products that require high stability and reliability will require SMD manufacturers to use nitrogen ovens for reflow soldering. In contrast, vacuum reflow soldering is in a vacuum environment for product soldering, mainly used to protect the product and the solder is not oxidised. The cost of vacuum reflow soldering is generally higher, but in some high-precision industries, such as military, aviation, automotive electronics, medical electronics, etc., more widely used.