Related to blind hole and buried hole production process

Related to blind hole and buried hole production process

I. Overview:

Blind hole, buried hole plate is mainly used for high-density, small microplate production, the purpose is to save line space, so as to achieve the purpose of reducing the size of the PCB,

Such as mobile phone board

Second, the classification:

A), laser drilling,

Causes of laser drilling:

A. Customer information required laser drilling;

B because the blind hole aperture is very small <= 6MIL, need to laser drilling.

C, special blind buried holes, such as L1 to L2 with blind holes, L2 to L3 have buried holes, it must be laser drilling.

2. Laser drilling principle: laser drilling is the use of sheet metal heat absorption of the plate will be vaporized or dissolved into a hole, so the plate must be absorbable, so the general RCC material, because the RCC without glass fiber cloth, The

3. RCC material Description: RCC material that is coated with resin copper foil: by electrolytic copper foil rough surface coated with a layer of unique properties of resin composition.

Laser drilling tool making requirements:

A). Laser is difficult to burn through the copper, so in the laser hole before drilling in the blind hole with the completion of the aperture and other large Cu Clearance.

B). The laser drilling positioning mark is added to the L2 / LN-1 layer, which is indicated on the MI Films tab.

C). Erosion of the blind hole film must be made with LDI, open materials to use LDI plate size.

5. Production process features:

One). When the total number of lines for the N, L2-Ln-1 layer by the normal plate process is completed,

B). Press the plate, gong finished after the process to the outside: ---> drill LDI positioning hole ---> dry film --->

---> laser drilling ---> drill hole ---> sink copper ---- (normal process).

Three holes blind board to pay attention to some of the special requirements:

1. resin plug blind hole: When the hole size is larger and the number of holes, the pressure plate, fill the hole requires a lot of resin, in order to prevent its impact plate thickness, R research requirements, can be used in the plate before the resin Will be buried in the hole pre-plug, plug hole should be based on green oil plug hole.