VeCS is based on the creation of slots to form multiple vertical connections on a denser area that is possible with current circuit board technology. The problem with bringing holes
The slots can be either through, blind or buried and can even be combined with Mircovias if required.
VeCS uses standard printed circuit board techniques to avoid capital imvestments and qualification of new processes.
The basic VeCS element is shown in 3D in the figure below. We call this the VeCS-1 element. Later we will show the possibilities of the Hybrid blind construction called VeCS-2.
The copper coloured areas are the vertcial traces running into the circuit board and are seperated using a second slot or hole. This creates a direct barrier for electron migration (CAF) between adjacent vertical traces as there is no path anymore available for the electron to travel. Depending on the sizes that can be achieved for the second caviety and positional accuracy traces can be as close as less then 0,1mm side to side. This is something not achievable by any other technology used today.
The slots dimensions are at the introduction of the technology 0,3mm. As we progress with the forming of the slots we expect that the milling process which we use today can be extended to slots of 0,2mm and below. For semiconductor packages we see needs of VeCS of 0,15mm and below. These structures will be in a blind or hybrid form.
In the next figures the results of the initial 0,3mm trials are shown. Important was the wandering of the bit on the back side of the 2,0mm thick board. This deviation was minimum and acceptable. The length of the slots in these images are just for development purposes and in "real' designs the slot length will be limited from a few mm to about 12 mm is the expectation.
The milling process is combined at with the drilling process, this can be done on the same machine or a specific drilling machine and a specific milling machine.
After cleaning and inspection of the slots and holes you can use the standard plating proces as you do today.
The advantage of the slots is that the fluid exchange in the slots is much better then in a small hole. Aspect Ratio issues are with VeCS-1 and VeCS-2 not a problem as fluid exchange is high in the cavities.
Materials and stackups
All known material used in the circuit board and semi-conductor packages can be used with VeCS. Dielectric and copper thicknesses as used in the inductry can be used. Not like Anylayer technology that is limited by the laserdrilling and plating process to limited thicknesses.