PQFP Metric quad flat-pack (MQFP): a QFP package with metric pin distribution Thin quad flat-pack (TQFP), a thinner version of LQFP Quad flat no-lead (QFN): smaller footprint than leaded equivalent Leadless chip carrier (LCC): contacts are recessed vertically to "wick-in" solder. Common in aviation electronics because of robustness to mechanical vibration. Micro leadframe package (MLP, MLF): with a 0.5 mm contact pitch, no leads (same as QFN) Power quad flat no-lead (PQFN): with exposed die-pads for heatsinking Grid arrays Ball grid array (BGA): A square or rectangular array of solder balls on one surface, ball spacing typically Fine-pitch ball grid array (FBGA): A square or rectangular array of solder balls on one surface Low-profile fine-pitch ball grid array (LFBGA): A square or rectangular array of solder balls on one surface, ball spacing typically 0.8 mm Micro ball grid array (μBGA): Ball spacing less than 1 mm Thin fine-pitch ball grid array (TFBGA): A square or rectangular array of solder balls on one surface, ball spacing typically 0.5 mm Land grid array (LGA): An array of bare lands only. Similar to in appearance to QFN, but mating is by spring pins within a socket rather than solder. Column grid array (CGA): A circuit package in which the input and output points are high-temperature solder cylinders or columns arranged in a grid pattern. Ceramic column grid array (CCGA): A circuit package in which the input and output points are high-temperature solder cylinders or columns arranged in a grid pattern. The body of the component is ceramic. Lead-less package (LLP): A package with metric pin distribution (0.5 mm pitch). Non-packaged devices Although surface-mount, these devices require specific process for assembly. Chip-on-board (COB), a bare silicon chip, that is usually an integrated circuit, is supplied without a package (which is usually a lead frame overmolded with epoxy) and is attached, often with epoxy, directly to a circuit board. The chip is then wire bonded and protected from mechanical damage and contamination by an epoxy "glob-top". Chip-on-flex (COF), a variation of COB, where a chip is mounted directly to a flex circuit. Tape-automated bonding process is also a chip-on-flex process as well. Chip-on-glass (COG), a variation of COB, where a chip, typically a liquid crystal display (LCD) controller, is mounted directly on glass. Chip-on-wire (COW), a variation of COB, where a chip, typically a LED or RFID chip, is mounted directly on wire, thus making