How do I Apply 3M ACF Adhesive?

ACF binds circuitry.

Anisotropic-conductive film (ACF) binds circuitry while maintaining electrical conductivity. ACF consists of adhesives that set after heating (thermosetting), adhesives that become soft when hot and hard when cold (thermoplastic) plus conductive particles. The incorporation of conductive particles allows circuitry to fully function because electricity flows freely through the adhesive. 3M manufactures 11 types of ACF for different substrates. However, all ACF adhesive films require three application stages: tacking, liner removal and bonding. All 3M ACF adhesives also require heat to bind two substrates together.

Things You'll Need

• Scissors
• Tweezers
• Razor blade
• Thermo-compression bonder or soldering iron

Instructions

1. Cut the ACF adhesive from the roll in desired size.

2. Stick the tacky side of the adhesive onto one substrate (with the liner facing outwards). Use tweezers if necessary. Press into place.

3. Remove adhesive liner by lifting a corner of the liner with a razor blade. Complete liner removal with tweezers.

4. Join the second substrate to the first and apply pressure to make a temporary bond.

5. Place substrates into a thermo-compression bonder to set the adhesive. ACF adhesive requires heat from 250 to 300 degrees Fahrenheit plus 290 psi of pressure. Although not specifically recommended by 3M, ACF may set with heat from a soldering iron plus pressure imposed by hand.

6. Allow adhesive to cool.

References

• 3M: ACF Adhesive 7303
• Flip Chip: Anisotropic Conductive Film Tutorial