Compression MOLDING PROCESS

Compression
MOLDING PROCESS
Confidential--All information property of Towa Corporation
1
Advantage of Compression Molding
Compression Mold
Transfer Mold
100%
Around 70%
No Stress
Stress by resin flow
No flow mark remain
Remain flow mark
Just mold recipe change
Necessary to tool change
Uniformity filler distribution
Un-uniform filler distribution
Compound usage
Stress to Die
&Wire
Flow Mark
Changeability of
Package
Thickness
Warpage
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2
~ Compression mold ~ feature
Transfer Mold Technology
Process
Pellet in to the pot, then melting resin push
in to the cavity by plunger
Resin flow speed is 3～10mm/s
Compression Mold Technology
Process
Resin is supplied in to the cavity directly.
and substrate comes in to contact with the melting resin.
・Resin flow is almost nothing, it’s good for fine pitch,
and long wire package.
Resin flow speed≒0
・It’s can molding by very low pressure effect of ＦＭ
Best solution for Low-K Die
・Less cleaning process effect of Release Film
Can be use wax less resin
Molding method
comparison
comparison
item
Molding
method
feasible to molding next generation package
thin and
fine pitch and long wire
Resin yield
large
Stack Die
Lequid resin
Low-K Die
package
compression mold
A
A
A
100%
transfer mold
B
B
B
40～60%
Confidential--All information property of Towa Corporation Best A ＞ B Better
3
High quality Molding: Achieved PKG thickness accuracy ±10 μm
Concept
Layout
Specification
Granular/Sheet
Compound
Liquid Resin
Uniform dispense granular
compounds OR put sheet
compound on the cavity
Uneven resin supply
Air flow
Uneven resin flow
Void
Chip off-set
No travel resin
Air flow
No defect
Travel Resin
Uneven
Filler segregation
Product defects
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Improve Resin utilization
Transfer Molding
Compression Molding
Approx. 40~60% resin usage
100% resin usage
Improved resin utilization and reduction of waste
material and disposal cost
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5
Reduction of Clearance of PKG
By reducing clearance between Die to PKG
Big Mold gap necessary
for compounds flow
Not necessary Mold gap by
Compression molding
Minimum
Mold Gap
over Die
Transfer molding
Compression molding
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6
Narrow down Gap between PKG & Chip
Outside appearance of 50μm Gap
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Warpage frequency table in Package (Comp vs Transfer)
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MSL in Package (Comp vs Transfer)
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