What does K [help K, kkk] often appear on the Internet mean? What does smt mean?

It is short for (help spread), which means to help him forward or share something and let more people know.

SMT is the abbreviation of Surface Mounted Technology, and it is the most popular technology and process in the electronic assembly industry at present. It compresses traditional electronic components into devices with a volume of only a few tenths, thus achieving high density, high reliability, miniaturization, low cost and automation in the production of electronic products. This miniaturized component is called SMY device (or SMC, chip device). The process of assembling components on printing (or other substrates) is called SMT process. Related assembly equipment is called SMT equipment.