Choosing the right IC package affects your PCB layout, thermal management, assembly process, and even long-term reliability. This quick reference covers the major through-hole and surface-mount package families.
Through-Hole Packages
- DIP (Dual In-line Package): The classic. 2.54mm pitch, 8-64 pins. Still used in prototyping, industrial controls, and reed relays.
- SIP (Single In-line Package): Single row of pins. Common in relay modules and power resistors.
- TO-220 / TO-247: Power packages with metal tab for heatsink mounting.
Surface-Mount Packages
- SOIC (Small Outline IC): 1.27mm pitch, gull-wing leads. Workhorse for analog and logic ICs.
- TSSOP / SSOP: 0.65mm pitch. Higher density than SOIC.
- QFN (Quad Flat No-leads): Exposed thermal pad underneath. Excellent thermal performance.
- BGA (Ball Grid Array): Solder balls under the package. Highest density but hardest to inspect.
- SOT-23 / SC-70: Tiny 3-6 pin packages for transistors and diodes.