石川金属 Product Lineup

Issues with Poor Wetting When solder wetting is poor, the bonding area decreases, leading to reduced joint reliability. Causes of poor wetting include issues with the reflow profile and degradation of components and substrates. Concept of the Reflow Profile A method called the "trapezoidal profile" is employed, which involves a long preheating and main heating process. While the heat resistance temperature of components is around 250°C, the melting point of solder is approximately 220°C. By extending the preheating zone, temperature differences due to the size of components are eliminated, preventing wetting failures due to insufficient heat in large components and failures due to overheating in small components. Degradation of Solder Paste During Preheating The typical preheating temperature is between 150°C and 180°C, with a preheating time of 90 to 120 seconds. During preheating, the flux in the solder paste begins to react due to heat, gradually losing its activity and reducing wettability. Therefore, it is ideal to conduct preheating at the lowest possible temperature and for the shortest time, within a range where the component temperature rises to about 240°C during main heating. Wetting Measures with Solder Materials The flux in solder paste contains activators tailored to the preheating and main heating temperatures. Our company offers pastes that demonstrate good wettability across a wide range of preheating temperatures and various components.

Void Issues Voids in solder joints are phenomena where gas generated during soldering remains trapped inside the solder joint. According to the industry standard IPC-A-610, voids up to 25% of the joint area are permissible, but for components such as power devices, reducing voids is necessary to improve heat dissipation efficiency and ensure joint reliability. Causes of Voids The causes of voids include: - Air bubbles trapped in non-wet areas - Decomposition gases from residual flux in the solder - Decomposition gases trapped in non-wet areas Measures Against Voids To prevent voids, it is essential to avoid creating non-wet areas on the substrate and components. It is important to manage them properly to prevent deterioration due to oxidation or moisture absorption during storage. Our company offers void-reducing solder paste made from materials with good wettability and low gas generation, so please contact us for more information.

The details below include information regarding "wet defects, bridges, and horns" in solder containing flux, so please check them.

The details below include information regarding "wet defects, bridges, and spikes" in solder with flux, so please check.

The following detailed information describes the flux dispersion in solder paste, so please check it.

The details below describe the cracking of flux residue in solder with flux and solder paste, so please check them.

The details below describe the cracking of flux residues in solder with rosin and solder paste, so please check them.