A6280 | Anti bleed Additive

Flash point considerations
We've used anti-bleeds in die attach pastes for years. We did not see nor did we get reports of the die attach pastes (or the components thereof) causing voids during curing. Additionally, the fact that the DMI products will cure into the matrix also reduces volatility concerns.

Can I use this as a preapplied/non mix product to reduce bleeding in die attach?

Right now the materials are 100% product, but, if you diluted them with a volatile solvent to aid in the application it might be possible. The process might be:

1. Apply 
2. Dry (not too hot)
3. Perform die attach to lock everything in place.

This could potentially work better than the mixed version as the resin would hit a roadblock when it encountered the relatively concentrated antibleed. If you get too much under the die attach you will likely destroy the adhesion. The tricky part would be how to prepare the solution and how to apply the antibleed mixture and keep it contained.

You can do some simple experiments to see if the concept holds promise:

• Dilute some antibleed with solvent (i.e. toluene)
• Dot some on a substrate and gently dry
• Dot some of the die attach paste and cure it up.

Good luck!

Can we use Anti bleed additives in Epoxy formulations

Typically, we recommend the anti-bleed based upon the type of substrate on which the adhesive is being used. The A6280 (and the A6225) have been shown to be effective on metallic surfaces like copper traces and difficult-to-manage gold. Other products may be more effective on printed circuit boards or solder mask material. However, this experience has been with free-radical cured resins (not epoxies) so chemical compatibility is a question to be answered.

• The DMI anti-bleed additives work by relying on the lack of compatibility of the siloxane portion of the molecule to encourage the product to migrate to the surface of the fillet where the functional group works to bond to the substrate to block bleed. 
• We believe the migration system will work in a similar manner for epoxy adhesives but the resin bleed blocking function may be at risk. 
• Our anti-bleed materials rely on either acid (p/n: A6150, A6265) or thiol (p/n: A6225, A6280) functionality to bond in and prevent bleed. Unfortunately, both of these groups react with epoxy resins. Reacting with epoxy (instead of the substrate) may reduce or eliminate the resin bleed functionality. 

Bottom line - we don't know if it will work. We are currently working on some modifications that could make anti bleeds even more epoxy friendly. This doesn't imply that the current formulations won't work with epoxies. But that if they don't we have more tricks up our sleeves.