Requirements for semiconductor reflow equipment and processes

In the semiconductor manufacturing process, reflow soldering is a very important process technology. Reflow soldering is mainly used to form reliable electrical connections on semiconductor chips to ensure the reliability and stability of electronic products. This article will introduce the definition, principle, equipment and process of semiconductor reflow soldering in detail.

(1) Meaning of semiconductor reflow

　 Semiconductor reflow is a process technology used to establish electrical connections on semiconductor chips. The process heats the solder to make it melt and flow, thereby connecting the pins on the chip to the pads on the circuit board. Reflow can be applied to packaging, assembly, and connecting semiconductor chips and surface mount components.

(2) Working principle of reflow soldering

  The working principle of reflow soldering mainly involves factors such as heat distribution, temperature control and solder characteristics. During the reflow soldering process, solder is first placed between the chip and the circuit board, and then the entire structure is placed in a heater for heating. The temperature controller of the heater adjusts the temperature according to a preset temperature curve to ensure temperature uniformity and stability throughout the process.

  Whenever the solder receives enough heat, it melts and flows, filling the gap between the chip pins and the circuit board pads. After cooling, the solder solidifies and forms a reliable electrical connection. To ensure the quality of the connection, the properties of the solder are also crucial, including appropriate fluidity, wettability, and melting point.

(3) Semiconductor reflow

　　Semiconductor reflow equipment is the core component of the reflow process. The ultimate goal is to help establish a reliable electrical connection between the circuit board and the chip by heating and melting the solder. Its main processes are as follows

1. Through the reflow operation, the solder paste printed on the metal surface of the bump is melted into a ball, thereby realizing the welding connection between the solder ball and the substrate;

2. After attaching the chip to the integrated circuit board, the chip and the circuit board can be connected together to realize chip packaging and integrated circuit manufacturing.

Semiconductor reflow soldering equipment is a reflow soldering process. Pay attention to the following points:

1. In order to ensure that the welding quality is not affected by dust and pollutants, the production environment must be kept clean.

2. In order to improve production efficiency, it is necessary to control production rhythm and output.

3. In order to prevent damage to components, the thermal shock they receive should be minimized.

4. In order to meet the mechanical and electrical performance requirements, the shape and size of the solder joints need to be controlled.

5. In order to avoid thermal damage and solder oxidation, the temperature and heating time of the heating area need to be controlled.