Storm Circuit has many univeristy customers,such as Columbia University,Oregon State University.We recently made a specail circuit boards for Carnegie Mellon University.What is the special? The PCB has chip-on-board package,that is we have to cut a fixed depth and make finishing over the exposed copper,also this circuit board is Rogers 4003 material.The surface finishing is also special ,it is not ENIG ,but it is i ENEPIG---ENEPIG-Electroless Nickel Electroless Palladium Immersion Gold.
The design is four layer PCB.Chip on board package is the the small chip will be loaded in the PCB.We have to cut from top to the second layer to expose copper and make ENEPIG on it. The cutout is very small,only 2*2mm, the curvature will be a bit big if we use normal rout bit ,and this is rejected by our valued customer. So,to cut this small area,we use laser cutting ,looks very nice.
16 layer PCB
Different Thickness PCB
6 Layer PCB Assembly
Via in Pad