In my last blog post, I noted that I had set up one of the earliest Surface Mount Technology (SMT) manufacturing facilities in the late 1970s. One of the main pieces of equipment we used was a Universal Instruments RhyMas II Model 4631 robotic placement system, shown below:
This system could place parts at the blazing speed of 300 per hour—which was incredibly fast for the time—but ancient compared to today’s chip shooters that can place over 100,000 parts per hour. The RhyMas system was controlled by a Tandy II 8 bit processor, and could place 1206 chip components (the only size being made at the time) from vibratory bowl feeders and had a placement accuracy of +/- 1 mil.
In the upper left-hand corner of the image above, you can see the vertical feeders for integrated circuits (ICs) that were part of a rotary structure to present the ICs to the pick and place head. It was our job to invent the aluminum tubes for the chip carrier components to prevent damage from electrostatic discharge (ESD), and also provide a feeder mechanism to the robot (plastic ESD tubes or tape and reel perform this function today).
Everything seemed to be working perfectly at the start, until we loaded 84 pin Leadless Chip Carriers (LCCCs) and forgot about the effect of gravity on the vertically loaded parts. When the pick-up mechanism lifted the part to present it for placement, the next five or six parts flew out the bottom of the feeder and across the room. Not a good plan for expensive parts! It didn’t take long for us to move toward sloped vibratory feeders to reduce the impact of gravity after that.
From there, this robot went on to build the Command Data Subsystem Memory Modules and the Attitude Control Electronics Processor for the Galileo Mission, as well as MIL-STD-1750A computers. As the First SMT robot, I’d say it did quite a memorable job.
This experience helped me to understand just how important it is to take all aspects of the use environment into consideration when performing a test or operating equipment. Though loading the LCCCs vertically seemed like the logical call at the time, underestimating the impact of gravity forced us to rethink our design. Since then, it’s become second nature for me to start thinking of any and all ways the usage environment can impact a particular design, right from the start of the project.
To learn more about how you can use environmental factors to provide a more thorough understanding of your equipment’s condition, make sure you download our free webinar on condition based maintenance (CBM) below!