Advanpack Solutions Pte Ltd

Wafer Level Packaging Methods

Pillar-CSP

Pillar-CSP

Advantages:

1.	APS’ Pillar-CSP uses the patented Pillar Bump structure as the interconnect base.
2.	This unique structure ensures a higher standoff for better reliability.
3.	It also increases the self-attenuation distance thereby reducing effects of alpha particle induced damages
4.	Various bump shapes and sizes are possible as well allowing performance enhancement through bump designs.
5.	The Pillar-CSP reliability is further enhanced by the epoxy-reinforced solder.

Pillar-CSP Process

Equipment Required :
- Flux and ball placement machine - Reflow Oven
- Spin Coater - Cure Oven - Plasma Machine

Pillar-CSP Guidelines

Design Guidelines

Pillar Bumps (Eutectic)

Bump Shape

Octagonal

Pillar Structure

Copper post + solder cap

Bump Height :	Copper post
	Solder cap

65 µm

35 µm

Bond Pad to Pass. Opening

14 µm Per Side (Min)

Pillar bump top CD (minimum)

250 µm

Pre-turned Solder Ball diameter (minimum)

250 µm

Bump pitch (minimum)

400 µm

Total solder height after reflow

180 µm

Epoxy Coating thickness

100 µm

Epoxy Coat Coplan

+/- 25 µm

RDL trace metal

0 µ

RDL trace thickness

5 µm

RDL trace width (min)

15 µm

RDL trace spacing (min)

15 µm