焊点

热电模块中的焊点是关键互连结构，通过熔化焊料合金在半导体粒子（P-N 对）、陶瓷基板和电导体之间形成永久的冶金结合。这些焊点必须保持低电阻以确保电流高效流动，同时承受来自珀尔帖效应和环境因素的热循环应力。焊点质量直接影响模块在温度控制系统等应用中的效率、可靠性和使用寿命。

焊点通过回流焊形成冶金结合，焊料合金熔化并润湿组件表面（通常是陶瓷基板上的铜焊盘和半导体粒子）。冷却后，焊料凝固形成金属间化合物层，提供电气连续性和机械粘附。在热电模块中，这些焊点必须适应加热/冷却循环中材料之间的热膨胀系数（CTE）失配，同时最小化寄生电阻。

Solder joints operate by creating metallurgical bonds through reflow soldering, where solder alloy melts and wets the surfaces of components (typically copper pads on ceramic substrates and semiconductor pellets). Upon cooling, the solder solidifies into an intermetallic compound layer that provides both electrical continuity and mechanical adhesion. In thermoelectric modules, these joints must accommodate coefficient of thermal expansion (CTE) mismatches between materials during heating/cooling cycles while minimizing parasitic electrical resistance.