When we simplify the capillary underfill process, underfilling boils down to the repeated depositing of very precise volumes of epoxy along the edges of microchips, as consistently as possible. If the underfill material placement is accurate, capillary action and heat curing will draw the material under the component, completing the process.To get more news about progressive cavity pump, you can visit brysonpump.com official website.

Since proper underfilling helps protect the finished product against damage from impact, moisture, thermal shock, and differences in the coefficient of thermal expansion (CTE) between chip packages and their carriers, the underfill process has become an essential part of the manufacturing of quality electronics.  If the purpose of the underfill process is ultimately to increase the lifespan of a product, then shouldn’t manufacturers in the electronics industry seek out the best underfill dispensing systems they can find?

So, if we’re hoping to choose the best underfill dispensing system for printed circuit board assembly, what exactly are the factors to look for? Time/Pressure Dispensers & Auger Valves Time/pressure dispensers and auger valves are accurate to +/- 10% and +/- 5%, respectively, but this level of variation may be too inconsistent for underfilling today’s tiny flip chips and ball grid arrays.

Jet Valves Jet valves, like the Techcon TS9800 Piezo Jet Valve System, are blazingly fast, depositing micro shots at small as 0.5 nanoliters at up to 1500 Hz continuous. These non-contact systems are literally 10x faster than auger valves, and even 2 – 3x faster than typical pneumatic jet valves. The TS9800 achieves a remarkable accuracy of up to +/- 3%, even at these breakneck speeds, and may be the ideal solution for high-volume operations trying to maximize throughput.

If underfill dispensing speed is required for your application, a jet valve might be the right system for you. Check out our blog, The Best and Fastest Jet Valve for Dispensing Underfill Applications to learn more.

For the ultimate is precision dispensing, only a progressive cavity system, like the Techcon TS8100 Progressive Cavity (PC) Pump, will achieve volumetric accuracy of +/- 1%. In a PC pump, a single-helix rotor turns inside a flexible rubber stator, molded with a twin-helix-shaped aperture. This forms a constantly shifting series of tightly sealed cavities, moving very precise volumes of material toward the pump outlet.

You will not find a more accurate dispensing system than a progressive cavity pump. PC pumps offer the level of repeatability required in the manufacturing of today’s high-reliability electronics for the automotive, aerospace, and military and defense industries.

Explore Continuous Flow Technology

In manufacturing, throughput is always important. Unlike other types of positive displacement/volumetric pumps and time/pressure valves, progressive cavity pumps offer continuous flow. As opposed to a filling and refilling approach, a PC pump with its internal material flow keeps throughput speeds consistently high.

Find A System Unaffected by Fluctuations in Air Pressure and Temperature

It is common for system output to be influenced by variations in fluid pressure. Small surges in pressure will suddenly increase the output of the underfill material and drop-back will suddenly decrease the output a few depositions later. These episodes will occur as the level of epoxy in the tube decreases, or if there is any unexpected change at the air pressure source.

Fluid pressure does not alter dispensing accuracy in a progressive cavity system. Dispensing volumes are dictated by the configuration of the rotor and stator, and the speed of the rotor rotation. Since the system is in constant motion, it provides nonstop material flow and is protected from variations of fluid pressure.

Underfill materials typically need to be protected from fluctuations in temperature. Underfill fluids are often heated to very specific temperatures to ensure proper capillary flow. And variation in the epoxy temperature will potentially impact the dispense volume as the changing temperature alters the fluid viscosity.

Thankfully, progressive cavity technology protects against these fluctuations. The tight seal between the rotor and stator ensures material in the cavities is protected from ambient temperatures, ensuring consistent and predictable dispense volumes around the chip being underfilled.