In display modules, arrayed ACF is the "premium" anisotropic conductive film — the only real drawback is price. This guide breaks down 5 key advantages and the application scenarios that call for it.
As TFT-LCD panels push narrower bottom bezels, the routing space shrinks. Techniques such as COF bonding, recessed Bump-Down design, and TDDI IC miniaturisation are used to achieve narrow bezels.
✅ Apply when: Pad-to-pad pitch ≤ 15 μm, or pad width ≤ 15 μm.
Free-dispersion ACF has particles randomly scattered in the resin layer; arrayed ACF arranges them uniformly in a regular pattern, leading to a much higher capture rate.
Free-dispersion particles tend to cluster and flow under bonding pressure; once the insulation layer is broken, particles sitting between adjacent bumps can cause inter-bump short circuits.
Arrayed ACF particles are aligned, so flow is limited and bridging risk is much lower.
✅ Apply when: Minimum IC bump-to-bump pitch ≤ 15 μm.
⚠️ "Minimum" means the smallest value across the entire IC bump array.
Consumer and automotive display modules face very different reliability tests:
Arrayed ACF provides stable, controllable particle count at every bond pad; the special resin formula also "locks" the particles, preventing flow under pressure and ensuring consistent conductivity across all pads.
✅ Apply when: High-reliability domains (automotive, medical, industrial).
As LCDs and ICs get thinner, COG bonding under heat and pressure produces larger deformation, leading to shallow or uneven indentation.
Multi-row bump designs (e.g. 4-row output bumps) are particularly affected — the outer 1–2 rows often show shallow indentation.
✅ Apply when: IC output-bump span ≥ 500 μm, or multi-row bump designs are used.