PCB News - HDI blind hole board manufacturing method

HDI blind hole board manufacturing method

With the development of electronic products to high density and high precision, the same requirements are put forward for circuit boards, which makes circuit boards gradually develop in the direction of HDI. The most effective way to increase PCB density is to reduce the number of through holes, and accurately set blind holes and buried holes.

1.HDI blind hole plate definition

a: In contrast to through holes, through holes refer to holes drilled through each layer, and HDI blind holes are non-drilled through holes.

b: HDI blind hole subdivision: blind hole (BLINDHOLE), buried hole BURIEDHOLE (outer layer is not visible);

c: Distinguish from the HDI circuit board production process: blind holes are drilled before pressing, and through holes are drilled after pressing.

2. Manufacturing method of circuit board

A: Drill belt:

(1): Select reference point: select the through hole (ie a hole in the first drill belt) as the unit reference hole.

(2): Each blind hole drilling belt needs to select a hole and mark its coordinates relative to the unit reference hole.

(3): Note that which drill belt corresponds to which layers: the unit sub-hole diagram and drill tip table must be marked, and the names of the front and back must be consistent; the sub-hole diagram cannot appear with abc, and the front is 1st, 2nd Indicates the situation.

Note that when the laser hole is sleeved with the inner buried hole, that is, the holes of the two drill belts are at the same position.

B: Production pnl board edge process hole:

Ordinary PCB multi-layer circuit board: the inner layer is not drilled;

(1): The rivets gh, aoigh, etgh are all shot after the board is eroded (beer out)

(2): target hole (drilled hole gh) ccd: the outer layer needs to be copper out, x-ray machine: directly punch out, and note that the long side is at least 11 inches.

All tooling holes are drilled, pay attention to rivets gh; need to be out to avoid misalignment. (Aoigh is also made for beer), the edge of the pnl board needs to be drilled to distinguish each board.

3. Film modification

(1): Indicate that the film has a positive film and a negative film:

General principle: HDI circuit board thickness is greater than 8mil (without copper connection) to follow the positive film process;

The thickness of the circuit board is less than 8mil (without copper) and the negative film process (thin board);

When the line thickness and the line gap are large, the copper thickness at d/f should be considered, not the bottom copper thickness.

The blind hole ring can be made 5mil, no need to make 7mil.

The inner independent pad corresponding to the blind hole needs to be retained.

Blind holes cannot be made without ring holes.

The Co., Ltd. is a circuit board manufacturer, focusing on the production of high-multilayer circuit boards, impedance PCB boards, thick copper boards, HDI boards, blind buried via circuit boards, FPC rigid-flex boards,PCB circuit board proofing and small and medium batch production Manufacturing.