- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
In-situ Measurements and Thermo-mechanical Simulation of Ti-6Al-4V Laser Solid Forming Processes
摘要： Residual stresses and distortions are two technical obstacles for popularizing the Additive Manufacturing (AM) technology. The evolution of the stresses in AM components during the thermal cycles of the metal depositing process is not yet clear, and more accurate in-situ measurements are necessary to calibrate and validate the numerical tools developed for its simulation. In this work a fully coupled thermo-mechanical analysis to simulate the Laser Solid Forming (LSF) process is carried out. At the same time, an exhaustive experimental campaign is launched to measure the temperature evolution at different locations, as well as the distortions and both the stress and strain fields. The thermal and mechanical responses of single-wall coupons under different process parameters are recorded and compared with the numerical models. Good agreement between the numerical results and the experimental measurements is obtained. Sensitivity analysis demonstrates that the AM process is significantly affected by the laser power and the feeding rate, while poorly influenced by the scanning speed.
关键词： Numerical simulation,Laser Solid Forming (LSF),Thermo-mechanical analysis,Additive manufacturing (AM),In-situ measurements of residual stresses
更新于2025-11-28 14:24:20
-
Development and optimization of the laser-assisted bonding process for a flip chip package
摘要： In a ?ne pitch ?ip chip package, a laser-assisted bonding (LAB) technology has recently been developed to overcome several reliability and throughput issues in the conventional mass re?ow (MR) and thermal compression bonding technology. This study investigated the LAB process for a ?ip chip package with a copper (Cu) pillar bump using numerical heat transfer and thermo-mechanical analysis. During the LAB process, the temperature of the silicon die was uniform across the entire surface and increased to 280 (cid:3)C within a few seconds; this was high enough to melt the solder. The heat in the die was quickly conducted to the substrate through the Cu pillar bumps. Meanwhile, the substrate temperature was low and remained constant. Therefore, a stable solder interconnection was quickly achieved with minimal stress and thermal damage to the package. The substrate thickness, the number of Cu bumps, and the bonding stage temperature were found to be important factors affecting the heat transfer behavior of the package. The temperature of the die decreased when a thinner substrate, a higher number of Cu bumps, and a lower bonding stage temperature were used. If the temperature of the die was not suf?ciently high, insuf?cient heat was transferred to the solder to melt it, resulting in incomplete solder joint formation. Thermo-mechanical analysis also showed that the LAB process produced lower warpage and thermo-mechanical strain than the conventional MR process. These results indicated that a LAB process using a selective local heating method would be bene?cial in reducing thermo-mechanical stress and increasing throughput for the ?ne pitch ?ip chip packages.
关键词： Laser-assisted bonding,Copper pillar bump,Thermo-mechanical analysis,Flip chip package,Heat transfer
更新于2025-09-11 14:15:04