Accurate and low cost circuit board assembly
In today’s world of space-conscious technology like flat-screen TVs, thin laptops and smart phones, the demand for space-saving printed circuit boards and system-on-a-chip (SOC) is on the rise. Assembling printed circuit boards requires repeatable performance, and extremely subtle precision that is often too expensive for educational and small business markets. At Brown University, Professor Harvey Silverman’s team devised a multi-axis circuit board assembly system to automate the process while staying within a suitable cost.
To accomplish the task of circuit board assembly, Professor Silverman needed a linear motion solution that could position tiny surface mount devices (SMD’s) such as capacitors and resistors of 0402 size (0.040 x 0.0240 inch), and accurately place them onto solder paste to adhere to the board. These tiny parts needed to be handled delicately, with the ability to adjust mid-operation to correct for misalignment. Finally, Professor Silverman needed to find a way to ensure all parts were in the right place.
The PBC Linear solution
Over the course of a year, Professor Silverman incorporated product assistance from PBC Linear application engineers to come up with a working solution. Three ML series lead screw driven mini-actuators were assembled in a 12 x 14 inch XYZ system, and then used to automate the surface mount assembly process. More specifically, two of the ML actuators would accurately determine the XY position while the third moved a vacuum needle, or part-grabber, up and down.