US 2019/0244837 A1Published application

Methods and apparatus for cleaning flip chip assemblies

AssigneeACM Research (Shanghai) Inc.

InventorsXiaoyan Zhang, Fuping Chen, Hui Wang

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Abstract

An apparatus for cleaning flip chip assemblies is provided. The apparatus comprises: a chuck assembly; a motor coupled to the chuck assembly by a spindle; at least one carrier for holding flip chips; at least one spray nozzle for directing DIW, a cleaning solution, a gas or a vapor. Embodiments of the invention further provide methods for cleaning flip chip assemblies. The method comprises: loading at least one flip chip to the flip chip carriers; rotating the chuck assembly at a rotation speed; flowing DIW for rinsing the flip chips; flowing a cleaning solution for removing the contaminants; applying ultrasonic/megasonic energy to the flip chips; blowing a gas or a vapor via the spray nozzles for drying the flip chips; bringing the flip chips out of the flip chip carriers.

Claims12

Dependent claims

A method for cleaning flip chip assemblies comprising:

loading at least one flip chip to one or more flip chip carriers held by a chuck assembly;
flowing a liquid feed for removing contaminants, the liquid feed comprising de-ionized water (DIW) or a cleaning solution, each respectively having a liquid density ρ and a surface tension coefficient σ;
rotating the chuck assembly at a rotation speed;
and
changing the rotation speed during a cleaning process based upon a length of the flip chip, a width of the flip chip, a radius of position of the flip chip carrier on the chuck, a space between two chip bond pads, a chuck spin time, a density of the liquid flowing during a stage of the cleaning process, and a liquid surface tension coefficient of the liquid flowing during the stage of the cleaning process, in which a low rotation speed and a high rotation speed are used alternately;
said low rotation speed Nl is in a range less than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
said high rotation speed Nh is in a range higher than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
where B denotes length of the flip chip, A denotes width of the flip chip, r denotes radius of position of the flip chip carrier on the chuck, h denotes space between two chip bond pads, t denotes chuck spin time, ρ denotes liquid density, and σ denotes liquid surface tension coefficient.

51 more elements

A method for cleaning flip chip assemblies comprising:

loading at least one flip chip to one or more flip chip carriers held by a chuck assembly;
flowing a liquid feed for removing contaminants, the liquid feed comprising de-ionized water (DIW) or a cleaning solution, each respectively having a liquid density ρ and a surface tension coefficient σ;
rotating the chuck assembly at a low rotation speed (Nl) during a first stage of the cleaning process applying DIW or the cleaning solution;
rotating the chuck assembly at a high rotation speed (Nh) during a second stage of the cleaning process applying the cleaning solution;
changing the rotation speed during the cleaning process stages based upon a length of the flip chip, a width of the flip chip, a radius of position of the flip chip carrier on the chuck, a space between two chip bond pads, a chuck spin time, a density of the liquid flowing during a stage of the cleaning process, and a liquid surface tension coefficient of the liquid flowing during the stage of the cleaning process, in which the low rotation speed and the high rotation speed are defined as follows;
said low rotation speed Nl is surface tension dominant and is in a range less than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
said high rotation speed Nh is centrifugal force dominant and is in a range higher than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
where B denotes length of the flip chip, A denotes width of the flip chip, r denotes radius of position of the flip chip carrier on the chuck, h denotes space between two chip bond pads, t denotes chuck spin time, ρ denotes liquid density, and σ denotes liquid surface tension coefficient, and
wherein the rotation speeds are independently determined based upon the liquid feed and time for each of the first stage and second stage.

52 more elements

A method for cleaning flip chip assemblies comprising:

loading at least one flip chip to one or more flip chip carriers, each for holding a flip chip, the at least one flip chip carrier including a fixer for fixing the flip chip;
driving a chuck assembly with a motor coupled to the chuck assembly by a spindle, wherein the fixer fixes the flip chip when the chuck assembly is rotating;
flowing a liquid feed for soaking the at least one flip chip and/or removing contaminants from the at least one flip chip during successive stages of a cleaning process, the liquid feed comprising de-ionized water (DIW) or a cleaning solution, each respectively having a liquid density ρ and a surface tension coefficient σ;
determining a critical rotation speed for each stage of the cleaning process;
rotating the chuck assembly at a low rotation speed (Nl) during a first stage of the cleaning process applying DIW or the cleaning solution, wherein Nl is in a range less than the critical rotation speed for the first stage of the cleaning process;
rotating the chuck assembly at a high rotation speed (Nh) during a second stage of the cleaning process applying the cleaning solution, wherein Nh is in a range higher than the critical rotation speed for the second stage of the cleaning process;
changing the rotation speed during the cleaning process stages based upon a length of the flip chip, a width of the flip chip, a radius of position of the flip chip carrier on the chuck, a space between two chip bond pads, a chuck spin time, a density of the liquid flowing during a stage of the cleaning process, and a liquid surface tension coefficient of the liquid flowing during the stage of the cleaning process, in which the low rotation speed and the high rotation speed are defined as follows;
said low rotation speed Nl is surface tension dominant and is in a range less than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
said high rotation speed Nh is centrifugal force dominant and is in a range higher than
60
×
(
2

σ
ρ


hAr
+
2

B
rt
2
)
1
2
2

π
;
where B denotes length of the flip chip, A denotes width of the flip chip, r denotes radius of position of the flip chip carrier on the chuck, h denotes space between two chip bond pads, t denotes chuck spin time, ρ denotes liquid density, and σ denotes liquid surface tension coefficient, and
wherein the rotation speeds are independently determined based upon the liquid feed and time for each of the first stage and second stage.

54 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/389,568Filed 19 Apr 2019
Priority: 20 Mar 2014
Published: 8 Aug 2019
Term ends: Not estimatedThe source records don’t support an estimate.

Classification10 codes

H10P 72/0414
For wet cleaning or washing: using mainly spraying means, e.g. nozzles
H10P 70/15
Cleaning before device manufacture, i.e. Begin-Of-Line process: by wet cleaning only
H10P 72/0404
Apparatus for fluid treatment: for general liquid treatment, e.g. etching followed by cleaning
H10W 72/01271
Of bump connectors, dummy bumps or thermal bumps: cleaning, e.g. oxide removal or de-smearing

Family

Application14/346,163Division · filed 20 Mar 2014
Application16/389,568Division
US 11,876,005 B2Related patent
US 2014/0224281 A1Published application
US 2019/0244837 A1This patent

From the US filing history. Foreign family members aren’t listed.

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