Invisible PCB Silkscreen

The FedEx van came today and we were super excited to see the reflow oven controller PCB coming back from the fab. It was sent using FedEx International Priority Pack which is way much faster than their Economy Pack. But, the moment we open the envelope we knew something is not right!

At first glance, we thought that we have forgotten to zip the gerber files together with the silkscreen layer. At a second closer look, the silkscreen which supposed to be striking yellow in color is there but poorly visible. All the boards has the same look and we can’t imagine anyone able to read them! So, we went back and check with the fab for clarification. After an hour or so going through investigation on the production floor, they told us it was due to the silkscreen material which was poor in quality. But, they promised us to manufacture another batch again (with boring white silkscreen) within 2 days and send them over. This add a few more days of delay for the reflow oven controller final release.  Even the Mini Ultra 8 MHz PCB that was sent out much later will reach our place latest by early next week using another fab in China. We would like apologize to everyone that has been waiting patiently.

A yellow silkscreen on green solder mask should look like this instead: