Integrated circuit packages

• SOIC - Small Outline Integrated Circuit. This has a dual in line configuration and gull wing leads with a pin spacing of 1.27 mm
• TSOP - Thin Small Outline Package. This package is thinner than the SOIC and has a smaller pin spacing of 0.5 mm
• SSOP - Shrink Small Outline Package. This has a pin spacing of 0.635 mm
• TSSOP - Thin Shrink Small Outline Package.
• PLCC - Plastic Leaded Chip Carrier. This type of package is square and uses J-lead pins with a spacing of 1.27 mm
• QSOP - Quarter-size Small Outline Package. It has a pin spacing of 0.635 mm
• VSOP - Very Small Outline Package. This is smaller than the QSOP and has pin spacing of 0.4, 0.5, or 0.65 mm.
• LQFP - Low profile Quad Flat Pack. This package has pins on all four sides. Pin spacing varies according to the IC, but the height is 1.4 mm.
• PQFP - Plastic Quad Flat Pack. A square plastic package with equal number of gull wing style pins on each side. Typically narrow spacing and often 44 or more pins. Normally used for VLSI circuits.
• CQFP - Ceramic Quad Flat Pack. A ceramic version of the PQFP.
• TQFP - Thin Quad Flat Pack. A thin version of the PQFP.
• BGA - Ball Grid Array. A package that uses pads underneath the package to make contact wit the printed circuit board.

Before soldering the pads appear as solder balls, giving rise to the name. By placing the pads underneath the package there is more room for them, thereby overcoming some of the problems of the very thin leads required for the quad flat packs. The ball spacing on BGAs is typically 1.27 mm.

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