General matters For all SMD or direct plug-in pads, there should not be too much tin on each pad, and it should form a smooth surface, but not bulge into a ball. For general patch pads, the thickness of the solder paste before welding is preferably 0.12mm (that is, the thickness of the steel mesh). For EP thermal pads, the amount of solder paste should be reduced by 50%. How to solder QFN and similar packages. Make sure there is no excess tin on the PCB and QFN component pads as much as possible, and use soldering tape to clean them. Apply an appropriate amount of tin (as much as possible as shown in the picture) on the pads around the PCB QFN. Place the QFN component to the corresponding position on the PCB. Use a heat gun to heat the QFN component and its surroundings to ensure that all solder paste is melted and soldered
Catalog: PCB
Symbol meaning A Detachable component or subassembly PCB Component AT Attenuator or isolator BR Bridge rectifier BT Battery C Capacitor CN Capacitor network D CR Diode thyristor DL Delay line DS Display universal light source lamp signal lamp F Fuse FB Ferrite beads FD Reference FL Filter G Generator or oscillator GN Generalized Network H Hardware – Screw Nut Washer HY Circulator Directional Coupler IR Infrared Diode J Jack – Connector The smallest removable connector in a pair Jack Connector – Connector May have male pin contacts and female socket
What is PIN Direction When creating a component library in Fusion 360 / EAGLE, you need to create a symbol (part of the electrical schematic). At this time, you need to set the symbol shape and number of terminals of the part. The item for setting the component terminal function is Direction. PIN Direction has the following nine options: Direction Full name type remarks nc Not Connected Empty pin heat dissipation/fixed pad in Input Input IC Input pin out Output Output IC Output pin io Input/Output Bidirectional GP
Common component library Frames.lbr Circuit diagram frame Supply2 Power supply and grounding Battery Battery RCL Resistor Capacitor Inductor Electrolytic Capacitor [R-EU C-EU CPOL LE] POT Potentiometer [TRIM US] Resistor-Net Exclusion Diode Diode [ZENER-DIODE] Triac Thyristor Transistor-NPN Transistor-PNP Transistor Transistor-FET Field effect tube LED Light-emitting diode Display-Ingbright seven-segment digital tube [7-SEG