Flux residue cleaning system and method

Patent metadata

Field	Value
Publication number	US-9406500-B2
Application number	US-201213369138-A
Country	US
Kind code	B2
Filing date	Feb 8, 2012
Priority date	Feb 8, 2012
Publication date	Aug 2, 2016
Grant date	Aug 2, 2016

Abstract

A flux residue cleaning system includes first and second immersion chambers, first and second spray chambers, and a drying chamber. The first immersion chamber softens an outer region of a flux residue formed around microbumps interposed between a wafer and a die when the wafer is immersed in a first chemical. The first spray chamber removes the outer region of the flux residue when the wafer is impinged upon by a first chemical spray in order to expose an inner region of the flux residue. The second immersion chamber softens the inner region of the flux residue when the wafer is immersed in a second chemical. The second spray chamber removes the inner region of the flux residue when the wafer is impinged upon by a second chemical spray in order to clean the wafer to a predetermined standard. The drying chamber dries the wafer.

First claim

What is claimed is:

1. A flux residue cleaning system, comprising:
a first immersion chamber configured to receive a wafer, the first immersion chamber adapted to soften an outer region of a flux residue formed around microbumps interposed between the wafer and a die when the wafer is immersed in a first chemical;
a first spray chamber adapted to receive the wafer from the first immersion chamber, the first spray chamber comprising a first sprayer, the first sprayer discharging a first chemical spray towards the wafer, the first chemical spray impinging on the flux residue to remove the outer region of the flux residue in order to expose an inner region of the flux residue;
a second immersion chamber adapted to receive the wafer from the first spray chamber, the second immersion chamber adapted to soften the inner region of the flux residue when the wafer is immersed in a second chemical;
a second spray chamber adapted to receive the wafer from the second immersion chamber, the second spray chamber comprising a second sprayer, the second sprayer discharging a second chemical spray towards the wafer, the second chemical spray impinging on the flux residue to remove the inner region of the flux residue in order to clean the wafer; and
a drying chamber adapted to receive the wafer from the second spray chamber, the drying chamber adapted to dry the wafer when the wafer is exposed to a flow of nitrogen;
wherein:
the second immersion chamber is different than the first immersion chamber;
the second spray chamber is different than the first spray chamber;
the first chemical spray comprises de-ionized (DI) water; and
the second chemical spray comprises at least one of DI water and isopropyl alcohol.

2. The flux residue cleaning system of claim 1 , wherein the first immersion chamber is equipped with a first sonic wave apparatus configured to propagate at least one of an ultrasonic wave or a megasonic wave in the first chemical to promote removal of the outer region of the flux residue.

3. The flux residue cleaning system of claim 1 , wherein the second immersion chamber is equipped with a second sonic wave apparatus configured to propagate at least one of an ultrasonic wave or a megasonic wave in the second chemical to promote removal of the inner region of the flux residue.

4. The flux residue cleaning system of claim 1 , wherein the first and second immersion chambers are each equipped with a sonic wave apparatus.

5. The flux residue cleaning system of claim 1 , wherein the first immersion chamber is configured to receive a plurality of the wafers simultaneously.

6. The flux residue cleaning system of claim 1 , wherein the second immersion chamber is configured to receive a plurality of the wafers simultaneously.

7. The flux residue cleaning system of claim 1 , wherein each of the first and second immersion chambers is configured to receive a plurality of the wafers simultaneously.

8. The flux residue cleaning system of claim 1 , further comprising a third spray chamber having a third sprayer, the third sprayer discharging a third chemical spray towards the wafer, the third chemical spray impinging on the flux residue to remove a portion of the outer region of the flux residue.

9. The flux residue cleaning system of claim 8 , further comprising a fourth spray chamber having a fourth sprayer, the fourth sprayer discharging a fourth chemical spray towards the wafer, the fourth chemical spray impinging on the flux residue to remove a portion of the inner region of the flux residue.

10. A flux residue cleaning system, comprising:
a first immersion chamber configured to soften an outer region of a flux residue formed around microbumps interposed between a wafer and a die when the wafer is immersed in a first chemical;
a first spray chamber configured to receive the wafer from the first immersion chamber, the first spray chamber comprising a first sprayer, the first sprayer directing drops of a first chemical spray towards the wafer, the drops of the first chemical spray impinging on the flux residue to remove a portion of the outer region of the flux residue;
an additional first spray chamber configured to receive the wafer from the first spray chamber, the additional first spray chamber comprising an additional first sprayer, the additional first sprayer directing drops of an additional first chemical spray towards the wafer, the drops of the additional first chemical spray impinging on the flux residue to remove a further portion of the outer region of the flux residue in order to expose an inner region of the flux residue;
a second immersion chamber configured to receive the wafer from the additional first spray chamber, the second immersion chamber adapted to soften the inner region of the flux residue when the wafer is immersed in a second chemical;
a second spray chamber configured to receive the wafer from the second immersion chamber, the second spray chamber comprising a second sprayer, the second sprayer directing drops of a second chemical spray towards the wafer, the drops of the second chemical spray impinging on the flux residue to remove a portion of the inner region of the flux residue;
an additional second spray chamber configured to receive the wafer from the second spray chamber, the additional second spray chamber comprising an additional second sprayer, the additional second sprayer directing drops of an additional second chemical spray towards the wafer, the drops of the additional second chemical spray impinging on the flux residue to remove a further portion of the inner region of the flux residue in order to clean the wafer;
a drying chamber configured to receive the wafer from the additional second spray chamber, the drying chamber adapted to dry the wafer when the wafer is exposed to a flow of nitrogen;
wherein:
the second chemical spray comprises de-ionized (DI) water; and
the first chemical spray comprises at least one of DI water and isopropyl alcohol.

11. The flux residue cleaning system of claim 10 , wherein the first immersion chamber is equipped with a first sonic wave apparatus configured to propagate at least one of an ultrasonic wave or a megasonic wave in the first chemical to promote removal of the outer region of the flux residue.

12. The flux residue cleaning system of claim 10 , wherein the second immersion chamber is equipped with a second sonic wave apparatus configured to propagate at least one of an ultrasonic wave or a megasonic wave in the second chemical to promote removal of the inner region of the flux residue.

13. The flux residue cleaning system of claim 10 , wherein the first and second immersion chambers are each equipped with a sonic wave apparatus.

14. The flux residue cleaning system of claim 10 , wherein the first immersion chamber is configured to receive a plurality of the wafers simultaneously.

15. The flux residue cleaning system of claim 10 , wherein the second immersion chamber is configured to receive a plurality of the wafers simultaneously.

16. The flux residue cleaning system of claim 10 , wherein each of the first and second immersion chambers is configured to receive a plurality of the wafers simultaneously.

17. A cleaning system comprising:
a first immersion chamber comprising a first chemical;
a first spray chamber adapted to receive a wafer from the first immersion chamber, the first spray chamber comprising:
a first sprayer configured to discharge a first chemical spray towards the wafer to remove an outer region of a flux residue formed around connectors interposed between the wafer and a die wh

Assignees

• Chen I-Ting
• Shih Ying-Ching
• Lu Szu Wei
• Lin Jing-Cheng
• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Chen I-Ting
• Shih Ying-Ching
• Lu Szu Wei
• Lin Jing-Cheng

Classifications

• H10W74/15

  on active surfaces of flip-chip devices, e.g. underfills · CPC title

• H10W72/07236

  Soldering or alloying · CPC title

• H10W72/072

  of bump connectors · CPC title

• H10W72/01271

  Cleaning, e.g. oxide removal or de-smearing · CPC title

• H10W90/724

  between a chip and a stacked insulating package substrate, interposer or RDL · CPC title