You might think that nothing would be worthless, but creating nothing is actually very useful for PCBA manufacturing. At our contract manufacturing facility we use vacuums in a few different places to ensure that we are building a reliable product for the customer.

The attached video shows a pair of Peeps (Marshmallows) being placed into a vacuum chamber at our facility.  When the vacuum is started the air bubbles in the marshmallow begin to expand and the Peeps grow in size.  The Peeps’ air bubbles reach an equilibrium and then they stop growing. The air bubbles begin to burst and the Peeps begin to shrink, and then the vacuum is released and the Peeps shrink to a fraction of their original size.

Much like the enlarging air bubbles of the Peep, the vacuum will pull out the air bubbles from the glop top, or encapsulation, which is placed over the wirebonds to protect them.  This helps to ensure that the material will completely surround the wirebonds and support them. For example, if we were to leave the bubbles in the encapsulation they could expand and crack the wirebonds during later reflow cycles.

Vacuums are also used in the baking process to help remove the moisture from the PCB’s.  These vacuum ovens are used when there is going to be a severe thermal shock to the PCBA that could cause the moisture in the PCB to quickly turn into steam within the PCBA.  This would cause the board to be ripped apart from the inside.  This failure mode has been minimized by the simple addition of baking steps that remove the moisture from the PCBA.

Overall, this is a great way to explain how we as contract manufacturers use various methods within the steps of production to ensure quality of our products. Why is quality so important? As a medical device manufacturer our products might be used inside a person or to help a doctor perform a procedure on a patient, which could possibly even be one of our own family members, so we take the steps necessary to ensure product reliability. With that said, even the simplest step such as a vacuum is extremely useful in our day to day operations.

Footnote: The Peeps still tasted good after this experiment, although they were fairly dense.