Required target layer thickness "F" / stub remainder "G"
If you need a special layer buildup, please keep to the following min. layer thickness of the layer in which the drilling stops (F).
If you do not need a special layer buildup, e.g. you are using our defined layer buildups, we will do all the necessary thickness calculations regarding the thickness of "F" and “G”.
Index Type Value min.
A Plated-through via Ø 200µm
B Backdrill Ø 400µm
C Copper clearance 150µm
D Ø-Difference circumf. 100µm
E Backdrill depth 200µm
F…
The backdrill process removes stubs from plated-through-holes (vias). Stubs are the unnecessary / unused portions of vias, which extend further than the last connected inner layer. Stubs can lead…
Advantages of Backdrill
Reduced deterministic jitter Lower bit error rate (BER) Less signal attenuation with improved impedance matching Increased channel bandwidth Increased data rates Reduced EMI…
For simulating stubs, as well as high-speed digital design layouts, the software ADS by Keysight Technologies can be used. ADS is capable of linear, non-linear and electromagnetic (2.5D and 3D)…
Pitch
The minimum pitch for Via-in-Pad solutions is 600µm (standard technology). This results of:
200µm min. drill diameter 400µm min. pad size 50µm min. solder-stop clearance 100µm min.…
Via-in-Pad Parameters
Standard Special production Special production
Filling IPC 4761 Type VII IPC 4761 Type VII none
Min. Drill-Ø 200µm 150µm 100µm
Min. Pad-Ø 400µm 350µm 300µm
Max. Drill-Ø…
The use of Via-in-Pad technology is increasingly influenced through the necessity of high-density BGAs (ball grid arrays) and the miniaturization of SMD chips. With a reliable Via Filling / Capping…
Advice
The milling tolerance is +/- 150µm Distance pad to pad: min. 250µm Milling gap within a panel: min. 10mm (see drawing) Most common surface: chemical gold (ENIG) Use the largest hole diameter…
