HDI Blind and Buried Vias  PCB Design Rules

HDI Design PCB

HDI PCB Design Rules of laminated structure for blind and buried vias

Blind and Buried Vias Rules 1

For the thickness of the core board, for all first-order blind holes with a core board of 0.10mm and a diameter of less than 0.25mm, use 100um RCC. For all blind holes with a core board of 0.13mm and a diameter of less than 0.25mm, it is recommended that customers use 100T RCC.

Blind and Buried Vias Rules 2

N+ structure blind buried hole plates, the laminated structure design should follow the same or similar thickness (thickness difference is less than 0.20mm). When the thickness of the dielectric layer in the N or M laminated structure is ≥0.40mm, the inner core plate should be used Instead, for the blind and buried hole plates that are pressed multiple times, the thickness matching of the last pressing must be considered in the engineering design.

HDI Rules 3

Blind and buried holes electroplating to control copper thickness, please engineering remarks: average 20um, single point greater than 18um.

HDI  Rules 4

Conventional FR4 materials, if a single core board does not have a blind buried hole structure, it is not possible to use the core board direct compression method for laminated design, and the PP+ inner core board design should be used: as shown in the figure below:

HDI Rules 5

In the second-order HDI process, the outer layer of the board must be negative-plated. (That is: the outer layer electroplating adopts negative film electroplating, the outer layer pattern adopts the negative film process, and the inner layer etching line is used to process the outer layer circuit)

HDI  Rules 6

Refer to “HDI, Mechanical Blind Buried Hole Preamplification Proportion Matters” for relevant regulations on the pre-amplification ratio of the inner core plate of multiple laminated panels.

HDI Rules 7

Laser drilling capability  4 MIL and 65 um RCC.

HDI Rules  8

The inner layer board using the PP+ inner core board pressing method, the board has a blind buried hole design and a surface copper thickness requirement to complete 1OZ copper thickness with 12um copper foil or 12um copper foil RCC, which will be immediately after the negative plating Meet the requirements;

HDI Rules 9

The inner layer, complete the RCC with 12um copper foil or 12um copper foil for HOZ copper thickness, go through the inner layer plating hole process, and then go through the negative film process to etch.

HDI Rules 10

The board has no blind and buried holes, only boards with copper thickness requirements, and can be processed directly with the copper foil thickness required by the customer, without the need for copper sinking and electroplating processing procedures.

HDI Rules 11

Panels that are directly pressed by the core, such as the panels that need to be electroplated, the inner core board should be made of copper and copper structure as much as possible.

HDI Rules 12

Please refer to “Supplementary Regulations for Outer Line Compensation of Blind Hole Plates” for the outer layer compensation of multiple press-bonded panels.

HDI Rules 13

All types of plated hole processes (through holes, blind holes, buried holes, etc.), regardless of plate thickness and aperture, the size of the plated film pad is unified as follows: drill diameter + 3mil (that is, increase 1.5 on one side mil).

HDI Rules 14

The second-order HDI board cannot contain an outer layer. The surface treatment methods are full-board gold plating (water gold), metalized edging, metalized slot, and negative pad process. If you have the above requirements, please communicate.

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