塑封集成电路因其是非气密性封装，封装材料热膨胀系数的不同以及被粘接材料表面能低，是造成塑封电路离层或开裂的内部原因。

First of all, the internal reason for the delamination or cracking is the different CTE of the packaging materials and the low surface energy of the adhesions.

youdao

人造金刚石由于其自身高的热导率、低的热膨胀系数和相对低的价格已成为制造新型散热材料的研究热点。

Synthetic diamond is competitive in heat dispersing materials, because it has high thermal conductivity, low coefficient of thermal expansion and lower price.

youdao

过共晶铝硅合金比重小、热膨胀系数低、耐磨性和体积稳定性好，是理想的活塞材料。

Hypereutectic Al-Si alloy which has small proportion, low coefficient of thermal expansion, good wear resistance and dimensional stability is an ideal piston material.

youdao