HDI Technology in Hole

High Density Interconnection
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Blind & Burried 9+2+9 Laser Drill
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Market Trend vs. Technology Solution

HDI Process Flow

Main Process of Build – up Layer

Construction Materials
MATERIAL TYPE
- FR 4 Tetra Function ( Tg. 130 – 140 ℃ )
- FR 4 High Tg ( Tg. 160 – 180 ℃ )
- RCC ( Tg. 150 ℃ & Tg. 185 ℃ )
- Ink ( VIL )
Comparison of Material
Prepreg | RCC | |
Low Cost | ++ | – |
Strength | ++ | + |
Hole wall roughness | – | + |
Laminating control | + | – |
Dielectric thickness | 45um ~ | 30um ~ 80um |
Smear residue on target pad | – | ++ |
Dielectric constant | 3.9 ~ 4.7 | 3.2 ~ 3.8 |
Shelf time | ++ | + |
Working PNL size | ++ | + |
Comparison of Via Technologies
Mechanical Drilling | Laser Drilling | |
Low Cost in Equipment | ++ | + |
Low Cost in Production | + | ++ |
Required Facilities | Drilling Machine | Laser Machine |
Consumable | Drill Bits, Backup Board | None |
Aspect Ratio | 9 | 1 |
Via Size Capacity | 200 um~ | 50~100um |
Speed | 140 H/min | 20,000 H/min |
Throughput | – | + |
Comparison of Blind Via
PREPREG | RCC |
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Build-up for 2 + N + 2
THROUGH HOLE | INNER LASER VIA | STACK HOLE |
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INNER VIA HOLE | SURFACE LASER VIA |
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Laser Via Quality

1+6+1 without buried, extend to 1+N+1

1+4+4+1 with buried via, extend to 1+N+N+1

Black Oxide Treatment

D.F. Strip
–
Etching

D.F. Exposure / Developing

Dry Film Lamination

I.V.H.Grinding( for thickness >= 60 mil )

I.V.H.Grinding( for thickness >= 60 mil )

Electro Plating

Electroless Copper Plating

I.V.H.(Inner Via Hole) Drilling

I.V.H.(Inner Via Hole) Drilling

Blind via Capability

2+4+2 Staggered via, extend to 2+N+2

2+4+2 laser via on laser via

Solder Mask Printing

Dry Film Lamination

Lamination

Prepreg Layup

Black Oxide Treatment

D.F. Exposure / Developing

Dry film, Exposure & DES

Electro Plating

Desmear / Electroless Copper Plating


Laser Drilling for Blind Via

D.F. Strip

Etching

D.F. Exposure / Developing
–
S/M Exposure / Developing

Surface Finish

Symbol Mask Printing

Inspection
–