In PCB production, high-temperature welding tunnel furnace is a crucial link. In order to improve welding quality and production efficiency, many companies choose to add nitrogen to the furnace. The nitrogen soldering furnace is mainly used for the soldering of complex circuit boards such as fine pitch, high density interconnect (HDT) and flip chip (BGA). This technology enables a precise welding process at high temperatures and reduces solder joint problems due to oxidation, such:

(1) inhibition of oxidation reaction

During the welding process, the high temperature environment will promote the oxidation reaction between the metal surface and the oxygen in the air, which will adversely affect the quality of the welded joint. By introducing nitrogen to create a low oxygen atmosphere, the oxygen in the welding furnace can be effectively replaced, and the oxygen concentration in the welding area can be significantly reduced, thereby inhibiting metal oxidation and improving the forming quality of the welded joint.

(2) Optimization of welding performance

As an inert gas, nitrogen has excellent heat transfer characteristics. Nitrogen is introduced into the reflow soldering process, which can promote the uniformity of temperature distribution in the welding area and make the solder joint more tightly and firmly. At the same time, the nitrogen environment can reduce the thermal stress in the welding process, reduce the formation probability of crack defects, and strengthen the welding reliability from the mechanical performance level.

(3) improve the solder process

InSMTIn reflow soldering, the performance of solder paste directly affects the connection quality of components and circuit boards. Nitrogen environment reduces the oxidation degree of solder paste through reduction reaction, and effectively improves its wetting ability and flow performance. This helps the solder material to more fully fill the fine gap between the pin and the pad, thereby enhancing the electrical continuity and structural stability of the solder joint.

(4) Reduce the void defect rate

The void defects in the welded joint will significantly weaken the mechanical properties and electrical conductivity. By controlling the oxygen content, nitrogen atmosphere reduces the oxidation products of solder paste at high temperature, and suppresses the formation and aggregation of bubbles in the welding process from the root, thus reducing the formation probability of cavity defects and realizing the systematic improvement of welding quality.

However, the process stability of nitrogen welding furnaces is highly dependent on the precise control of nitrogen purity and oxygen content. Process specifications require that the oxygen content in the furnace be maintained1000ppmBelow, high-precision welding conditions need to strictly control the oxygen concentration.50ppmwithin the threshold. Traditional detection devices have technical limitations on key indicators such as high temperature tolerance and micro-range measurement accuracy, while limiting current oxygen sensors haveSO-B0-001With innovative structural design, it provides targeted solutions for nitrogen welding furnaces:

(1) Maximum temperature resistance350℃, covering most of the welding furnace100~300℃ working temperature range

(2)10-1000ppm ultra-fine range coverage, ± 20ppm detection deviation, to achieve 0.01 level of oxygen content fluctuation monitoring

(3) Using a miniaturized package design, the sensor body only50px³, can be integrated into the furnace body without feeling

(4) Single-point calibration technology simplifies the maintenance process, with a life of 20,000 hours to meet the continuous operation requirements of the production line.

WelcomeShenzhenThe official website consults the Sensore limiting current sensor. In addition to SO-B0-001, the measuring range of the limiting current sensor covers 10ppm ~ 96% oxygen, and has a variety of packages to adapt to various working and installation environments. It can be applied to electrical industry, biomedicine, storage and transportation, safety monitoring and other fields. The sensors can also be paired with a General Purpose Sensor Board (GSB) or custom circuitry for fast system integration. For complete model parameters or industry solutions, please contact us.