Bill of Material (BOM) is a document that describes the product structure in data format. The BOM for SMT processing includes the name of the material, the quantity and the number of the mounting position. BOM is an important basis for the programming of the SMT machine and the confirmation of IPQC.

DIP Package, (Dual in-line Package), also known as dual in-line package technology, refers to the use of dual in-line package In the form of integrated circuit chips, the vast majority of small and medium-sized integrated circuits are in this form of packaging, the number of pins is generally not more than 100.The DIP-packaged CPU chip has two rows of pins that need to be inserted into the chip socket with the DIP structure.

SMT (Surface Mount Technology), also known as Surface Mount technology in English, or SMT for short, is a circuit mounting technology that attaches surface mount components to a specified position on the printed circuit board surface.Specifically, it is first coated with solder paste on the printed board circuit plate, and then the surface mount element device is accurately placed on the solder paste coated pad, through heating the printed circuit board until the solder paste melts, after cooling, the interconnection between the element and the printed board is realized.

In the 1980s, SMT production technology is becoming more and more perfect, the mass production of components for surface mounting technology, the price has dropped significantly, a variety of technical performance, low price equipment have come into the market, with SMT assembled electronic products have small size, good performance, full function, low price advantage, so SMT as a new generation of electronic mounting technology, It is widely used in the assembly of electronic products in various fields such as aviation, aerospace, communication, computer, medical electronics, automobile, office automation, household appliances and so on.

SMD (Surface Mounted Devices), in the initial stage of the production of electronic circuit boards, through the hole assembly is completely completed by manual.When the first automated machines were introduced, they could accommodate some simple pin components, but complex components still needed to be placed manually for wave soldering.Surface mount components were introduced about twenty years ago and ushered in a new era.From passive components to active components and integrated circuits, they all eventually became surface mounted devices (SMD) and could be assembled with pickup and drop devices.For a long time it was thought that all pin components could eventually be packaged in SMD.