Chip on board

[1] Chip on board eliminates the packaging of individual semiconductor devices, which allows a completed product to be less costly, lighter, and more compact.

In some cases, COB construction improves the operation of radio frequency systems by reducing the inductance and capacitance of integrated circuit leads.

It consists of a drop of specially formulated epoxy[4] or resin deposited over a semiconductor chip and its wire bonds, to provide mechanical support and exclude contaminants such as fingerprint residues which could disrupt circuit operation.

[5] In "tape-automated bonding", thin flat metal tape leads are attached to the semiconductor device pads, then welded to the printed circuit board.

COB LEDs could be compared with multi chip modules or hybrid integrated circuits since all three can incorporate multiple dies into a single unit.

The PCB of a quartz watch. The clock IC is under the drop of black epoxy.
The cartridge board for "Tennis" for the Xavix / XaviXPORT console. Unlike other consoles, the main processor for the system is located on the video game cartridges.
A chip-on-board (COB) covered with dark epoxy
High power COB LEDs supplied at a low current level with 5% of maximum current. Showing 40 single blue power LEDs below the yellow surface