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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

Adhesive Dispensing

Views: 2293



Adhesive Dispensing | 22 February, 2006


Why positive displacement technique cannot be used for underfill dispensing? Which is the best technique to dispense underfill?

This message was posted via the Electronics Forum @

reply »


Adhesive Dispensing | 23 February, 2006

"The three dispensing pumps used for encapsulation are the air/time syringe, rotary positive displacement pump (RPDP) and the linear piston pump. Each of these methods of dispensing offer different attributes but the most accurate method is the linear pump because it is a positive displacement device. Since it is positive displacement, variations in epoxy viscosity over time or temperature do not effect the dispensing accuracy. This property is extremely valuable in high volume production environments."

For more look here: 1998_08_asymtek_best_practices_underfill.pdf

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

reply »


Adhesive Dispensing | 23 February, 2006

Positive Displacement Pump technology is in fact used for the underfill process.

Both Camalot Systems and Asymtek both use them. Asymtek also has the Jetter and Camalot has the Multi-Piston Pump, specifically designed for underfill applications. These other pump technologies provide greater speed and accuracy (in the case of Camalot's MPP, speed & accuracy) in deposition than traditional PDP technology developed for SMD adhesive, solderpaste and Ag epoxy applications.

reply »

IPC Certification Training Schedule

Fluid Dispensers