The tasks of drillings in the production of PCBs are different. Firstly, they are used for precise positioning and for mounting the component leads at plug in assemblage during the production sequence. From double sided PCBs, the drillings are necessary for through plating. Therefore the drillings have to be as precise as possible, so the drilling pattern and the image can be assigned accurately. We offer you drillings from 0,15 mm.
drilling types
pth (plated trough holes)
- through-hole plating
- connection of the layers by a metal-plated hole in the base material
npth (non plated through hole)
- non plated through holes which do not have a metal-plated connection from one side to the other side of a PCB
buried vias
- connection between the inner layers
- no contact to the outer layers
blind vias
- connection between one outer layer and minimum one inner layer
- no through hole
- attention: Aspect Ratio 1:1
shallow countersunk
- drilled to a certain depth
- usually not plated
conical countersunk
- drilling tapers downwards
- different angles possible
Aspect Ratio
The Aspect Ratio is the mathematical ratio of the drill diameter to the contactable drilling depth. For plated through holes the Aspect Ratio is 1:5, an Aspect Ratio of 1:8 is possible. For blind vias the Aspect Ratio is 1:1 and must be maintained.
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