Tool/software:
Hello,
I am trying to design a PCB in KiCAD using the antenna described in application note 043. The application note reads "It is also recommended to use the same thickness and type of PCB material as used in the reference design. Information about the PCB can be found in a separate readme file included in the reference design." (p4)
I have a hard time making sense of the readme file CC2511_USB_Dongle_Reference_Design_readme_1_3 which says the following about board stackup :
PCB DESCRIPTION:1-2 LAYER PCB 0.25 MM NOMINAL
2-3 LAYER PCB 0.50 MM NOMINAL
3-4 LAYER PCB 0.25 MM NOMINAL
THICKNESS FR4 WITH 35um Cu PER LAYER
Dimensions in mil (0.001 inch)
DOUBLE SIDE SOLDER MASK,
DOUBLE SIDE SILKSCREEN,
8 MIL MIN TRACE WIDTH AND 6 MIL MIN ISOLATION
Dielectric constant for FR4 is 4.5
If I understand correctly, the first dielectric and last dielectric layers have 0.25mm nominal thickness, while the middle one has 0.5mm. With the 4 copper layers of 0.035mm and the 2 layers of solder mask (0.01mm each) that sums up to 1.16mm total thickness, which is not standard. The closest standard thickness is 1.2mm. Where are the 0.04mm that are missing ? Am I forgetting something ?
