HDI PCB / BLINDBURIED VIA HOLE PCB / BVH PCB

SPEEDAPCB has been focusing on the production of various PTH plated through hole PCB, buried via hole PCB and blind via hole PCB, and hdi pcb prototype.



When it comes to blind and buried hole circuit boards, everyone thinks of HDI boards. Generally, there are more blind and buried hole circuit boards used in mobile phones or navigation instruments. Such PCB boards require high technical content and accurate accuracy. Of course, the price is compared with other It is also high for multilayer circuit boards.



HDI high density interconnect pcb : 1 n 1, 1 1 n 1 1, 2 n 2, 3 n 3,



Features of BlindBuried Via Hole PCB

Blind Via Hole is the connection between the outermost circuit in the PCB and the adjacent inner layer with a plated hole. Because the opposite side cannot be seen, it is called blind pass. In order to increase the space utilization between the circuit layers of the board, blind holes come in handy. The blind hole is a via hole to the surface of the printed board.



Buried Via Hole, the connection between any circuit layers in the PCB, but there is no conduction with the outer layer, that is, there is no meaning of a via hole extending to the surface of the circuit board.



The blind holes are located on the top and bottom surfaces of the circuit board and have a certain depth. They are used to connect the surface layer circuits to the inner layer circuits below. The depth of the holes generally has a prescribed ratio aperture. This manufacturing method requires special attention, and the drilling depth must be just right. Failure to pay attention will cause difficulties in plating inside the hole. Therefore, few factories will adopt this production method. In fact, it is possible to drill the holes of the circuit layers that need to be connected beforehand, and then glue them together, but they need more precise positioning and alignment devices.



This manufacturing process cannot be achieved by bonding the circuit boards and then drilling. It is necessary to perform the drilling operation at the individual circuit layer, firstly locally bond the inner layer, then perform plating treatment, and finally all the bonding. Because the operation process is more laborious than the original vias and blind holes, the price is also the most expensive. This manufacturing process is usually only used for high-density circuit boards, increasing the space utilization of other circuit layers.



In the PCB manufacturing process, drilling is very important. The simple understanding of drilling is to drill the required via holes on the copper clad board, which has the function of providing electrical connections and fixing devices. If the operation of the via is caused by incorrect operation, the device cannot be fixed on the circuit board, which will affect the use of the circuit board, and the entire board will be scrapped. Therefore, the process of drilling is very important.



Parameters of BlindBuried Via Hole PCB

Items Capability.

Max board size 580X700mm

Boar Material FR-4,Aluminum, High Tg  FR4,CEM3,etc.

Min trace width/ space inner layer 4mil/4mil0.1mm/0.1mm

Min PAD inner layer 5 mil0.13mm

Min thicknessinner layer 4 mil0.1mm

Inner copper thickness 0.54 oz

Outer copper thickness 0.46 oz

Finished board thickness 0.4-3.2 mm

Board thickness tolerance control ±0.10 mm ±0.10 mm

±10% ±10%

±10% ±10%

Inner layer treatment brown oxidation

Layer count Capability 1-30 LAYER

alignment between ML ±2mil

Drill hole diameter 0.15mm-0.65mm

Aspect ratio of plated hole 10:01

Hole precision ±2 mil±0.05mm

tolerance for Slot ±3 mil±0.75mm

Hole diameter tolerancePTH ±3 mil±0.075mm

Hole diameter toleranceNPTH ±1mil±0.025mm

Max Aspect Ratio for PTH 8:01

Hole wall copper thickness 15-50um

Alignment of outer layers 4mil/4mil

Min trace width/space for outer layer 4mil/4mil

Tolerance of Etching /-10%

Thickness of solder mask on trace

Thickness of solder mask at trace corner ?0.2mil5um

Hardness of solder mask On base material ? 1.2mil

6H Finished thickness

Alignment of solder mask film ±2mil /-50um

Min width of solder mask bridge 4mil100um

Max hole with solder plug 0.5mm

Surface treatment HAL Lead or Lead free, immersion Gold, Immersion Nickel, Electric Gold finger, plated Gold, OSP, Immersion Silver.carbon oil,etc.

Max Nickel thickness for Gold finger 280u7um

Max gold thickness for Gold finger 30u0.75um

Nickel thickness in Immersion Gold 120u/240u3um/6um

Gold thickness in Immersion Gold 2u/6u0.05um/0.15um

Impedance control and its tolerance 50±10%,75±10%,100±10% 110±10%

Trace Anti-stripped strength ?61B/in?107g/mm

bow and twist 0.75%



SPEEDA Technology is a professional printed circuit board supplier. We provide Double Sided PCB, Multilayer PCB, hdi pcb board, hdi printed circuit boards, hdi circuit boards, buried via pcb, buried vias pcb and so on. Want to know more Please contact us.