Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Recommendation for Lead Free Epoxy used for Bonding & Underfill?

Views: 1250

#39544

Recommendation for Lead Free Epoxy used for Bonding & Underfill? | 6 February, 2006

Hi everybody! Just want to ask some recommendation if which epoxy is advisable to be used for bonding and underfill for BGA's at Lead Free Process. Currently, we only used Loctite 3515 for high temp curing for leaded process. How about for Lead free process does anybody know any ideal epoxy with higher curing temp than that of the 3515 @ 220C for 15 sec.?

I worry that when lead free BGA's or CSP with 3515 epoxy as underfill the epoxy will cure first before the BGA ball melt causing a highup elongated balls problem for the lead free BGA.

reply »

#39567

Recommendation for Lead Free Epoxy used for Bonding & Underfill? | 7 February, 2006

We agree that curing Loctite 3515 at lead-free temperatures is not a good idea. For lead-free, we know of some no-flow underfills, but no capillary flow underfills. Contact your underfill supplier for recommendations.

When you have this conversation be sure to consider an epoxy that contains flux. Look here: http://www.cooksonsemi.com/pdfs/No%20Flow%20Underfill%20ECTC%202002.pdf

We have no relationship, nor receive benefit from the company referenced above.

reply »

SMT Machines

Reflow Oven