74 2007 / August

Bumping

(Solder Bump)

(Under Bump Metallurgy UBM)

(Sputtering) (Electroplating)

(Bumping Market)

( ) (Electroless

Nickel/Gold E-Ni/Au) UBM

(High Vacuum) (Photolithography)

(E-Ni/Au)

(Flip Chip)

(Wafer Level Chip Scale Packaging WLCSP)

(UBM)

(Solderable Surface)

(Diffusion Barrier Layer) (Sputtering)

AlNiVCu (Electroplating Copper) UBM

90%

(Electroless Nickel/Gold)

UBM

/

(Flip

Chip) (Wafer Level Chip Scale

Packaging WLCSP)

(1) ( ) (2)

( 50 WPH(Wafers per hour)) (25

Wafers/Cassette) (3) (High Reliability)

(Nickel Barrier)

200mm Wa-

fer

UBM

(Double Zincation Process)

Fraunhofer Institute IZM [1]

UBM

1. (Al Clean)

2. (Al Etch)

3. -I (Zincation-I)

4. (Zinc Strip)

200mm wafer (Electroless Nickel/Gold)

76 2007 / August

5. -II (Zincation-II)

6. (Electroless Nickel)

7. (Electroless Gold)

IZM

[2,3,4,5]

1. (Al 100%)

2. (Si 0.5~1%)

3. (Cu 0.5~2%)

4.

(Galvanic Reaction)

(Electrochemical Cell) (Potential)

(Micro-Cell)

1970 0.5%Cu

(Limit Electro-Migration)

(Control Grain Growth)

[2]

0.5%Cu

(Potential Issue)

(Ground Pad)

(Inductive

Potential) (1)

(SiO2)/ (Si3N4) (2)

(Wafer Backside PR Coating)

(Al Pad)

(Photovoltaic Effect)

(Light Isolation)

( )( )

(Grand Plas-

tic Technology Corp.) 8 Wafer

(In-

Line Monitoring System)

UBM (IZM)[1]

772007 / August

pH

(E-Ni/Au Process)

(Al pad cleaning process)

(Organic

Residuals) (Diluted Sulfuric

Acid)

(Silicon Based Contaminants)

(1) (2)

(3)

(Al Pad Etching Process)(Native Oxide)

0.4µm ~ 8µm

( 2~8µm)

( 0.4~2µm)

1µm 80%

1µm

(Grain Size)

(Interface Area)

(Etch-Rate)

(Selectively Directional Etch)

1µm

/ (

)

(High Reliability)

pH 0.05pH

UBM (Solder Bump)

(Probe) (Electrical Test)

(Over-Etching)

I (Zincation I)/ (ZincStrip)/ II (Zincation II)

( )

(Zinc Oxide) (CO2)

(zinc Carbonate)

(Small

Crystal)

( )

(Active)

792007 / August

(Chemical

Plating)

(Autocatalytic Plating)

(NaH2PO2)

pH

(H2PO3-)

(NaH2PO2)

Sodium Boronhydride (NaBH4)

(N2H4)

(HCHO)

Dimethylamineborane(DMAB)

Diethylamineborane(DEAB) ( )

80 2007 / August

(Ni Concentration) pH

( )

(E-Ni/Au)

UBM

(Wet process)

(Equipment Cost)

(Chemical Cost)

(Equipment Cost)

(1)

(Up Time) (2)

(3)

(Bumping Market)

(GPTC)

(Chemical Cost)

(1)

( )

(

) (2)

SST-AP/Taiwan

(Xintec Technology) (ASE)

Xintec

ASE

(ITRI)

(David Hsu) (Grand Plastic Tech-

nology Corporation GPTC )

13 (03)5972353 ext: 255

david_hsu@gptc.com.tw

(Jesse Chan)(President of GPTC)

MSEE

(Clyde Yen ) (Vice

President of GPTC)

1. Andreas Osteman, “Electroless Nickel Bump”, Fraunhofer

Institute IZM, Germany, 2002.

2. A.J.G. Strandjord, M. Johnson, H.Lu, D. Lawhead, R.

Hanson, and R. Yassir, Flipchip International, LLC.

Phoenix, Arizona, 85034, 2003.

3. G. Motulla, “A Low Cost Bumping Service Based on

Electroless Nickel and Solder Printing,” Proc. IEMT/IMC

Symp., Omiya, Japan, 1997.

4. T. Oppert, E. Zakel, T. Teutsch, "A Roadmap to Low Cost

Flip-Chip and CSP using Electroless Ni/Au," Proceedings

of the International Electronics Manufacturing Technol-

ogy Symposium (IEMT) Symposium, Omiya, Japan, April

15-17, 1998.

5. R. Heinz, E. Klusmann, H. Meyer, R. Schulz, "PECVD of

Transition Metals for the Production of High-Density

Circuits," Surface and Coatings Technology, 116-119

(1999).