There are three common types of drilled holes in the printed circuit board: PCB through hole plating, blind via hole, and buried via hole. Therefore, PCBs are classified according to drilling methods and can be divided into plated through-hole PCB, blind via hole PCB, and Buried via hole PCB.
PTH is the most common drilling method, and it is common in various types of PCBs. SPEEDAPCB has been focusing on the production of various PTH (plated through hole PCB-PTH PCB), buried via hole PCB and blind via hole PCB.
Plated Through Hole, the copper foil lines between conductive patterns in different layers of the circuit board are connected or connected with this type of hole, but the copper legs of the component lead or other reinforced materials cannot be inserted. The PCB is formed by the accumulation of many copper foil layers. The copper foil layers cannot communicate with each other because each layer of copper foil is covered with an insulating layer, so they need to rely on via for signal connection.
The through hole of the circuit board must pass through the plug hole to meet the customer's needs. In changing the traditional aluminum sheet plugging process, the solder mask and plug hole on the circuit board surface are completed with a white net to make its production more stable and the quality more reliable , More perfect to use. The vias help the circuits to be connected to each other. With the rapid development of the electronics industry, higher requirements are also placed on the PCB manufacturing process and surface mount technology. The plugging process for vias came into being, and at the same time, it must meet the following requirements:
1. Only copper is required in the hole, solder plug can be plugged or not;
2. There must be tin-lead in the hole, with a certain thickness requirement (4um), to avoid solder mask ink entering the hole, causing tin beads to be hidden in the hole;
3. The through hole must have a solder resist ink plug hole, opaque, no tin rings and beads, and must be flat.
Through-hole boards are common in all fields and are one of the most common PCBs.
Generally, the mobile phone board or PDA board has a board that uses a combination of blind and buried holes. The buried hole can reduce the probability of signal interference, maintain the continuity of the transmission line's characteristic impedance, and save routing space. Circuit board design. This type of board requires high technical content and accurate accuracy, so relatively speaking, the requirements for factory equipment are much higher than ordinary multilayer boards, and the cost of such circuit boards will be much higher than ordinary Shelf should be high.
|Max board size||580X700mm|
|Boar Material||FR-4,Aluminum, High Tg FR4,CEM3,etc.|
|Min trace width/ space (inner layer)||4mil/4mil(0.1mm/0.1mm)|
|Min PAD (inner layer)||5 mil(0.13mm)|
|Min thickness(inner layer)||4 mil(0.1mm)|
|Inner copper thickness||0.5~4 oz|
|Outer copper thickness||0.4~6 oz|
|Finished board thickness||0.4-3.2 mm|
|±0.10 mm||±0.10 mm|
|Board thickness tolerance control||±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 tolerance(PTH)||±3 mil(±0.075mm)|
|Hole diameter tolerance(NPTH)||±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||≥0.2mil(5um)|
|Hardness of solder mask||On base material||≤+1.2mil|
|Alignment of solder mask film||±2mil(+/-50um)|
|Min width of solder mask bridge||4mil(100um)|
|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||280u"(7um)|
|Max gold thickness for Gold finger||30u"(0.75um)|
|Nickel thickness in Immersion Gold||120u"/240u"(3um/6um)|
|Gold thickness in Immersion Gold||2u"/6u"(0.05um/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%|