Flip Chips

Flip Chip describes the method of electrically connecting the die to the package carrier. The package carrier, either substrate or leadframe, then provides the connection from the die to the exterior of the package. The interconnection between die and carrier in flip chip packaging is made through a conductive bump that is placed directly on the die surface. The bumped die is then flipped over and placed face down, with the bumps connecting to the carrier. After the die is soldered, underfill is applied between the die and the substrate, around the solder bumps. The underfill is designed to contract the stress in the solder joints caused by the difference in thermal expansion between the silicon die and carrier.

UBM is the Al/NiV/Cu (under bump metallization) covering about 1% of the wafer which is under the bumps only. Nitride passivation is an invisible glass-like protective coating over 99% of the wafer, except under the bumps. The bumps will not stick to the Nitride, only the UBM. Nitride coating is standard for all Flip Chip wafers.

Flip Chips
Part Numbers:	FA10-200x200 FA10-400x400	PB08-200x200 PB08-400x400
Die Size	200 x 200 mils 400 x 400 mils	200 x 200 mils 400 x 400 mils
Bump Pitch	254 Âµm, 10 mil	203 Âµm, 8 mil
Passivation Via	80 Âµm	73 Âµm
UBM Diameter	102 Âµm	95 Âµm
Bump Height	120 Âµm	98 Âµm
Bump Diameter	135 Âµm	120 Âµm
No. of Bumps	317	88
Final Metal Pad Size Thickness Type	127 x 127 Âµm	115 x 115 Âµm
Metal Composition	98/1/1 Al/Cu/Si	98/1/1 Al/Cu/Si
Packaging
Uncut Wafer*	5" Wafer 200 x 200 mils (344Die) 400 x 400 mils (86 Die)	5" Wafer 200 x 200 mils (344 Die) 400x400mil (86 Die)
Tray	Sawed 5" Wafer 36 per tray 200 x 200 9 per tray 400 x 400 Waffle Pack	Sawed 5" Wafer 36 per tray 200 x 200 9 per tray 400x400 Waffle Pack
Tape and Reel	Call For Availability	Call For Availability

Notes

* * Die count represents expected yield per wafer.

* All die is packaged in waffle pack trays unless otherwise specified.

* All test wafers are currently 5" diameter and are 0.635mm thick. Passivation is one-micron thick plasma Nitride with round via openings.

* The potential multiple is the number of die repeats on the wafer. With the wafer orientated flat down, a right hand coordinate system applies.

* Die size is from scribe line to center-to-center. Scribe width is 0.05mm passivated. Each bump is electrically connected to one other bump and isolated from all others to facilitate electrical test.

* Bump pitch is defined as center-to-center distance between passivation openings.

* Bump height is defined as silicon surface to the top of the bump.

* Bump diameter is defined as the maximum diameter.

* UBM = Under Bump Metallurgy

* Lead-free parts are available with 95.5% Sn/ 3.5% Ag/ 1.0% Cu alloy.

* Unbumped wafers are available upon special request.

Part Number System

* Add "WR" to end of part number for Wafer Cut and left in Seal Ring.

* Add "TR" to end of part number for die on Tape and Reel.

* Add "EUT" to end of part number for Eutectic.

* Add "LF2" to end of part number for Lead-Free.

* Add "W" to end of part number for Uncut Wafer.

* Add "unbumped" to end of part number for unbumped wafer/die.

FCT Bump Structure

Data Sheets

Flip Chips

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