China Wholesale Custom Circuit Board Factories - 8 Layer ENIG Impedance Control PCB 16978 – Huihe

Deficiencies of the blind buried vias

The main problem of blind buried via is the high cost. In contrast, buried holes cost less than blind holes, but the use of both types of holes can significantly increase the cost of a board. The cost increase is due to the more complex manufacturing process of the blind buried hole, that is, the increase in manufacturing processes also leads to the increase in testing and inspection processes.

Buried Via

Buried vias are used to connect different inner layers, but have no connection with the outermost layer.

A separate drill file must be generated for each level of buried hole. The ratio of hole depth to aperture (aspect ratio/thickness-diameter ratio) must be less than or equal to 12.

The keyhole determines the depth of the keyhole, the maximum distance between different inner layers.

In general, the larger the inner hole ring, the more stable and reliable the connection.

Blind buried vias

The main problem of blind buried via is the high cost. In contrast, buried holes cost less than blind holes, but the use of both types of holes can significantly increase the cost of a board. The cost increase is due to the more complex manufacturing process of the blind buried hole, that is, the increase in manufacturing processes also leads to the increase in testing and inspection processes.

A: buried vias

B: Laminated buried via (not recommended)

C: Cross buried via

Equipment display

Automatic Plating Line

PTH line

LDI

CCD Exposure Machine

The advantage of blind Vias and buried Vias for engineers is the increase of component density without increasing layer number and size of circuit board. For electronic products with narrow space and small design tolerance, blind hole design is a good choice. The use of such holes helps the circuit design engineer to design a reasonable hole/pad ratio to avoid excessive ratios.

Application

Communications

Security electronics

Railtransit