Many electronic components have not yet been surface mounted using SMD. For this reason, SMT must accommodate some through-hole components. Surface mount components, active and passive, when attached to a substrate, form three main types of SMT assemblies – commonly referred to as Type I, Type II and Type III. The various types are processed in a different order, and all three types require different equipment.
1. Type III SMT assemblies contain only discrete surface mount components (resistors, capacitors and transistors) glued to the bottom side.
2.Type I components contain surface mount components only. Components can be single-sided or double-sided.
3. Type II components are a combination of Type III and Type I. It usually does not contain any active surface mount devices on the bottom side, but can contain discrete surface mount devices on the bottom side.
If the pitch is large and fine, the complexity of SMT assembly in electronic equipment will increase.
Ultra-fine pitch, QFP (Quad Flat Pack), TCP (Tape Carrier Package) or BGA (Ball Grid Array) and very small chip components (0603 or 0402 or smaller) are used for these components as well as traditional (50 mil pitch )) surface mount package.
Processes for all three surface mounts include – adhesives, solder paste, placement, soldering and cleaning followed by inspection, testing and repair
Chengyuan Industrial Automation, a professional SMT equipment manufacturer.
Post time: Mar-29-2023