Knowledge about SMT Components
Ⅰ. Introduction of SMT components
1. Small outline transistor (SOT)
Surface mount transistor with small outline package structure.
2. Small outline diode (SOD)
Adopt the surface mount diode of small outline package structure.
3. Chip (rectangular chip component)
There are no leads at both ends, with soldered ends, and a surface-mounted component with a thin rectangular shape.
4. Small outline package (SOP)
A small-profile molded plastic package with wing-shaped or J-shaped short leads on both sides of a surface mount component package.
5. Quad flat package (QFP)
There are wing-shaped short leads on four sides, and the lead pitch is 1.00, 0.80, 0.65, 0.50, 0.40, 0.30mm and other plastic package thin surface mount integrated circuits.
6. Fine pitch
No more than 0.5mm lead pitch.
7. Lead coplanarity
Refers to the vertical height deviation of the pins of surface-mounted components, that is, the vertical distance between the top of the pin and the plane formed by the bottom of the three pins.
Ⅱ. Types of SMT components
In the SMT production process, employees will connect more than a hundred kinds of components. Understanding these components is very useful for us to make no mistakes or make little mistakes in our work. Now, with the popularization of SMT technology, almost all kinds of electronic components are packaged in SMT. The electronic components that the company currently uses most are resistor (R), capacitor (C) (capacitors include ceramic capacitors-C/C, tantalum capacitors-T/C, electrolytic capacitors-E/C), diodes (D), Zener diode (ZD), transistor (Q), varistor (VR), inductor (L), transformer (T), microphone (MIC), receiver (RX), Integrated circuit (IC), speaker (SPK), crystal oscillator (XL), etc. In SMT, we can divide it into the following categories:
Resistor, capacitor, diode, transistor, connector, coil, IC, switch, etc.