upper package是什么意思

用法例句

Achieving closer flatness of upper package by improving the air-driven automatic feeding device;

改进空气自动送料机提高上盖平面度

Taking mobile front cover as the example,introduced the flow sheet of processing sample used the method of SLS.

并以手机上盖为例,分析了运用SLS工艺加工样品的流程,并指出了网络化、标准化是该项技术今后的发展方向。

This article discussed some questions in the structural design of the vehicles segment top head platform.

本文探讨了车辆段上盖平台在结构设计中应注意的问题。