MAY 2002

Asymtek Receives Patents for Co-Axial Air Dispensing Technique

Carlsbad, CA -Asymtek recently received patents for the co-axial air process on their Century® Selective Flux dispensing system. The co-axial technique is designed to increase the contact area between a viscous liquid and a substrate by utilizing single or multiple bursts of pressurized air. The pressurized air, delivered through a specialized nozzle, causes the droplets of dispensed material to spread, resulting in a consistent thin layer of flux (or other viscous liquid) on a substrate. A thin layer of flux provides a more reliable connection for electrical components and reduces the manufacturing costs of printed circuit boards.

"This latest patent will make the surface tension issue involved with low viscosity fluid jetting almost obsolete," explained Bill Donges, Asymtek's Product Manager of Conformal Coating. "There are two secondary benefits of this patent: the first benefit is increased speed of the dispensing process, the second is a thinner film deposition. This non-contact process will benefit the user by increasing the amount of parts processed per hour (UPH), and producing less material waste."

Though suitable for other applications, this dispensing method was specifically developed for dispensing solder flux onto a printed circuit board (PCB). To maximize the reliability of the solder connections between the electrical components and circuits on the PCB, a thin layer of solder flux needs to be applied prior to soldering. Since solder flux has high surface tension, it does not flatten appreciably upon contact with the substrate. Instead, the dispensing operation leaves a relatively tall droplet with a substantially semi-spherical shape and a small contact area. As a result, it is difficult to produce a thin layer of solder flux using conventional, non-contact dispensers and conventional solder flux. This patented nozzle provides a solution to this challenge.

This is Donges' eleventh patent earned while working at Nordson Corporation. During his 30-year employment with Nordson, he worked in the Corporate Electrical Group (CRE), designing products like valve controls, temperature controllers, and high voltage supplies. From the CRE, Donges moved to the Automotive Business Group. For the next 12 years, Donges worked in Nordson's Electronics Business Group, where the development of selective conformal coating automation in the United States began. He was very involved with setting the standards for selective conformal coating at Asymtek and spent five years in selective flux dispensing market development. Donges has a BA degree from the Electronic Technology Institute in Cleveland, Ohio.

Asymtek supplies award-winning automated fluid dispensing systems to the semiconductor, surface mount, electronics packaging and industrial markets. They are committed to offer total dispensing solutions and local support to customers throughout the world. A complete review of Asymtek's automated fluid dispensing systems may be found on their Web site at http://www.asymtek.com.

back to top