COB (chip-on-board) mounts a chip directly onto the substrate. Depending on the substrate used, COB can also be called COG (chip-on-glass) and COF (chip-on-flex). Mainly used with LEDs, the benefits of COB are its small size, LED intensity, uniformity, and heat dissipation, leading to longer-lasting LEDs.
Reflective Pocket in PCB for LED Die Attach (COB)
Improve output efficiency of LED lighting
Avoid photonic absorption and scattering over the pocket wall
Reflective MCPCB for LED Backlight (COB)
Improve LED light guide efficiency
Avoid loss by surface reflection, absorption and scattering
MCPCB with Thermal Conductive Pillar (Non-COB)
Improve LED thermal dissipation
Allow LED to work in extreme environmental conditions:
1) Climate - Arizona summer
2) Installation - limited space for thermal diffusion
Our COB manufacturing process consists of three steps:
We mount or attach the die to the board or substrate.
We connect the wires between die and substrate for thermosonic (Au or Cu) ball bending and ultrasonic (Al) wedge bending.
We dispense chemical liquid (usually epoxy) over die and wires to protect against chemical and mechanical damage.
COBs offer better performance due to its small size and a reduction in connections and solder joints, limiting the resistance. COBs also reduce cost due to its size with higher reliability and better heat dissipation.
Light Bar Structural