Chip on board

The PCB of a quartz watch. The clock IC is under the drop of black epoxy.

Chip on board (COB) is a method of circuit board manufacturing in which the integrated circuits (e.g. microprocessors) are attached (wired, bonded directly) to a printed circuit board, and covered by a blob of epoxy.[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.

COB effectively merges two levels of electronic packaging: level 1 (components) and level 2 (wiring boards), and may be referred to as "level 1.5".[2]

  1. ^ "How Chip-On-Boards are Made - learn.sparkfun.com". learn.sparkfun.com. Retrieved 2022-05-08.
  2. ^ John H. Lau, Chip On Board: Technology for Multichip Modules, Springer Science & Business Media, 1994 ISBN 0442014414 pages 1-3