Opportunities and Challenges for Fan-out Panel Level Packaging … · 2018-06-11 · Challenges for Panel Packaging assembly compression molding carrier preparation debonding redistri-bution

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September 2015 Tanja Braun

ForschungsschwerpunktTechnologien der Mikroperipherik

Opportunities and Challenges for Fan-out Panel Level Packaging

(FOPLP)

T. Braun (1), M. Töpper (1), S. Raatz (1), S. Voges (2), R. Kahle (2), V. Bader (1), J. Bauer (1), K.-F. Becker (1), T. Thomas (2), R. Aschenbrenner (1), K.-D. Lang (2)

(1) Fraunhofer Institute for Reliability and MicrointegrationGustav-Meyer-Allee 25, 13355 Berlin, Germany

e-mail: [email protected] phone: +49-30/464 03 244 fax.: +49-30/464 03 254

(2) Technical University Berlin, Microperipheric Center

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Outline

Motivation for Panel Level Packaging

PLP Results

Assembly on 24”x18” Panel Level

Compress ion Molding

Die Shift

Redistribution Outlook

Summary: Advantages & Challenges for FOPLP

Outlook

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PLP MOTIVATION

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FOWLP/FOPLP Process Flow Options

Die assembly on carrier

Wafer/panel overmolding

Carrier release

RDL (e.g. thin film, PCB based, …), balling, singulation

Apply thermal release tape on carrier Apply release layer on carrier

RDL (e.g. thin film, PCB based, …)



Carrier release, balling, singulation

Mold first RDL first

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Roadmap Fan-Out Panel Level Packaging

Source: Yole

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Challenges for Panel Packaging

assemblycompress ion

moldingcarrier

preparationdebonding

redistri-bution

handling, thinning & s ingulation

Eq

uip

me

nt

Ma

teri

al • Carrier

steel, glass,..?• Thermo

release tape Alternatives?

• EMC liquid,

granular, sheet?

• Dielectric polymers

liquid or film? photosensitive

or not?• Sputter targets• Plating

• Handling carrier

Tape or other material

Temporary adhesives

• Tape laminator

Available automatic equipment?

• Pick and Place Accuracy on

panel size?

• Material application

Dispensing, sprinkle, …

• Molding Uniformity,

thickness control, …

• Debonder Available

automatic equipment?

• Lithography Stepper, laser

ablation, LDI• Sputtering,

plating Thickness

variation, lines & spaces

• Thinning & Dicing

Available automatic equipment?

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From Wafer to Panel Size for Fan-out Packaging

24“ x 18“610 x 457 mm²

12“300 mm8“6“

Wafer Technologies PCB Technologies

Panel Technologies

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IZM Wafer Level Packaging Line (RDL)

for Wafer Sizes 100 mm / 150 mm / 200mm / 300 mm

Sputter Spin Coater Mask Aligner Wafer Plating Wet Etching

Spin CoaterSpin Coater N2 Oven RIEMask Aligner

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IZM Panel Level Embedding Line

from Wafer Scale to Panel Scale 610 x 456 mm²/24”x18”

Datacon evo/

ASM Siplace CA3

Mahr OMS 600/

IMPEX proX3

WL: Towa up to 8”

PL: APIC up to 18”x24”

incl. 12” WL

Lauffer/

Bürkle

Siemens Microbeam/

Schmoll Picodrill with

HYPER RAPID 50

Ramgraber automatic

plating line

Schmoll MX1 Orbotech

Paragon Ultra 200

SchmidCREAMET 600

CI 2 S3

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PLP RESULTS

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FOWLP/FOPLP Process Flow Steps



Carrier release

RDL (e.g. thin film, PCB based, …), balling, singulation

Apply thermal release tape on carrier Apply release layer on carrier

RDL (e.g. thin film, PCB based, …)



Carrier release, balling, singulation

Mold first RDL first

24”x18”

24”x18”

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High Speed Assembly on 24”x18”

Assembly of dies and fiducials

5.680 chips (2 x 3 x 0.25 mm³) have

been placed on the panel

Assembly speed of

~ 6.500 chips/h using one collect and

place 20-nozzle revolver head

using four assembly heads maximum

assembly speed could be accelerated

up to 32.000 chips/h

Assembled reconfigured 18”x24” panel

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Assembly Strategies on 18”x 24”

G1 G2

G3

B A

B AB A

B A C

CC

C

B

initial fiducial dies

A

-300 -200 -100 0 100 200 300

-0,10

-0,08

-0,06

-0,04

-0,02

0,00

0,02

0,04

0,06

0,08

0,10

x [

mm

]

x-position [mm]

-200 -100 0 100 200

-0,10

-0,08

-0,06

-0,04

-0,02

0,00

0,02

0,04

0,06

0,08

0,10

y [

mm

]

y-position [mm]

-300 -200 -100 0 100 200 300

-0,10

-0,08

-0,06

-0,04

-0,02

0,00

0,02

0,04

0,06

0,08

0,10

x [

mm

]

x-position [mm]

-200 -100 0 100 200

-0,10

-0,08

-0,06

-0,04

-0,02

0,00

0,02

0,04

0,06

0,08

0,10

y [

mm

]

y-position [mm]

Assembly Option A:three fiducial dies have been placed first and in a second step all other dies have been place in reference to

the initial fiducial dies

Assembly Option B:Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four segments (A, B,

C) have been placed in a second step in reference to the global fiducials. Finally all other dies are

assembled in reference to the local fiducials.

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Compression Molding - Principle

2 – 15 min

Short cycle time Constant temperature

-> no heating or cooling ramps No full compression pressure over

longer time PMC and mold release extra process

steps

Vacuum

Mold Tool

Mold Tool

Wafer

Cavity

Release Film

EMC

process profileprocess principle

panel mold machine

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Molding Compounds for Large Area Encapsulation

Liquid Compression Molding Compounds

Granular Compression Molding Compounds

Sheet LaminationMolding Compounds

Standard material for wafer level embedding

Paste-like material is dispensed in the cavity and flows during tool closing and compression of the tooling

Limited potential for large area due to complex dispense patterns needed and longer flow length?

€€

Standard material for MAP compression molding

Granular material is distributed nearly homo-geneously all over the cavity and melts and the droplets have to fuse during closing and compression of the tooling

No limitations for large area application

€

Standard material for wafer level embedding

Material sheets are melting and only flow around dies for encapsulation

Sheets in defined thicknesses/volume

No limitations for large area application

€€€

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Material Evaluation for Compression Molding

properties A B

liquid granular

filler content 89 wt.-% 90 wt.-%

filler cut size 75 µm 55 µm

CTE1 7,5 ppm/K 7,2 ppm/K

CTE1 33 ppm/K 30 ppm/K

Tg 165 C 175 C

flexural modulus @ RT 22 GPa 27 GPa

mold temperature 125 C 125 C

inmold cure time 600 s 420 s

PMC temperature 125 C 125 h

PMC time 1 h 2 h40 60 80 100 120 140 160 180

-0.04

-0.02

0.00

material B

material A

heat

flow

[W

/g]

temperature [°C]

20 40 60 80 100 12010

2

103

104

105

106

107

material B

vis

cosity

[Pa

s]

temperature [°C]

material A

DSC Rheology

Comparable cured material properties

Comparable low mold and cure temperature but different cure times

Significant different flow properties with much lower viscosity of the liquid compound

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Mold Compound Application

Liquid EMC Granular EMCs

Dispensing of dot patterns

Volume control by insitu weighing

Homogeneous spreading

Volume control by weighing

Manually by sieve technology, automatically by vibrating unit

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Compression Molding on 12”/300 mm Wafer Size


Dispensing of one dot in the center

Homogeneous filling without flow marks or knit lines

Homogeneous spreading

Homogeneous filling without flow marks or knit lines

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Compression Molding on 24”x18” Panel SizeLiquid EMC – Evaluation of dot size pattern

Evaluation of different dot patterns – target panel thickness of 450 µm (~ 250 g)

Dispense time with state of the art material and equipment 20 – 30 min

1 2

3 4

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Compression Molding on 24”x18” Panel SizeLiquid EMC – Evaluation of dot size pattern

Complete filling of the 24”x18” panel feasible

Strong flow marks and knit lines for all patterns, dispense time too long

Process and material optimization needed

1 2

3 4

Strong flow marks and knit lines



Panel broken along knit line


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Compression Molding on 24”x18” Panel SizeGranular EMC – Evaluation of spreading

Evaluation of two different spreading patterns – target panel thickness of 450 µm (~ 250 g)

o Dot pattern

o Homogeneous spreading

Application time with state of the art material and manual equipment 5 – 10 min

1 2

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Compression Molding on 24”x18” Panel SizeGranular EMC – Evaluation of spreading

Complete filling of the 24”x18” panel feasible

Granular compound distribution has also an influence on flow marks

Homogeneous distribution of the compound required

1 2

Flow marks in the shape of the granular dot pattern

No flow marks

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Compression Molding on 24”x18” Panel Size


Molded panels with liquid EMC show less flow marks as blank panels

Significant marks only visible at the panel edges where no dies are assembled

Molding of panels with assembled dies (die thickness: 250 µm, mold thickness: 450 m)

Molded panels with granular EMC show nearly no flow marks

Encapsulation of assembled panels with liquid and granular compound feasible

Granular EMC show slightly better mold results and shorter process time

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Die Shift on 18”x 24”

initial fiducial dies

A

Assembly Option A:three fiducial dies have been placed first and in a second step all other dies have been place

in reference to the initial fiducial dies

-300 -200 -100 0 100 200 300

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

x [

mm

]

x-position [mm]

-200 -100 0 100 200

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

y [

mm

]

y-position [mm]

Linear die shift in x- and y-direction => compensation possible

Same slope in in x- and y-direction

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G1 G2

G3

B A

B AB A

B A C

CC

C

B

Assembly Option B:Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four

segments (A, B, C) have been placed in a second step in reference to the global fiducials.

Finally all other dies are assembled in reference to the local fiducials.

-300 -200 -100 0 100 200 300

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

x [

mm

]

x-position [mm]

-200 -100 0 100 200

-0,6

-0,5

-0,4

-0,3

-0,2

-0,1

0,0

0,1

0,2

0,3

0,4

0,5

0,6

y [

mm

]

y-position [mm]

Reference to global fiducials

Comparable results to assembly option A

Linear die shift in x- and y-direction => compensation possible

Same slope in in x- and y-direction

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G1 G2

G3

B A

B AB A

B A C

CC

C

B

Assembly Option B:Global fiducials (G1, G2 and G3) have been assembled first. Local fiducial dies for the four

segments (A, B, C) have been placed in a second step in reference to the global fiducials.

Finally all other dies are assembled in reference to the local fiducials.

Reference to local fiducials

Linear die shift in x- and y-direction in each quarter => compensation possible

Same slopes in all quarters

Lower die shift

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RDL on Panel Size – Quo Vadis?

24“ x 18“610 x 457 mm²

12“300 mm8“6“

PCB based technologies Already available on panel level – proof of concept has

been demonstrated Currently limited to 10 µm lines and spaces Maskless adaptable processes possible No die surface opening possible for e.g. sensors or LEDs Low cost potential

Thin film technologies Proven and established process for FOWLP Fine line structuring down to 2 µm lines and spaces Die surface opening possible for e.g. sensors or LEDs Quite expensive equipment

No simple upscaling of technologies from WL to PL

Not one solution for everything

Application defined – “best of both worlds”

New materials in combination with new processes must be developed

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PLP SUMMARY & OUTLOOK

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• Electrical Performance: Proof of concept for very RF-Modules beyond 30 GHz.

• Improved wiring and I/O: There is several decades of experience in fine line wiring and interconnection technology in the IC industry that can be leveraged for packaging technology.

• Standardization:Standardization is key for embedding die package to multi-sourcing

• Thermo-mechanical reliability : Improved reliability compared to FIWLP due to additional plastic packaging

• Cost:Cost advantages are perceived with the ultra-miniaturized approach proposed when coupled with large area, high throughput and high volume production.

Advantages for FOWLP and PLP

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Challenges for FOPLP

• Warpage ( Assembly, Manufacturability)• Heterogeneous materials and non-symmetric structure cause bow• Polymer materials with adapted CTE& modulus and low shrinkage are

required• Optimized layer sequence and design required

• Accuracy/Resolution ( Miniaturization)• Improved optical recognition systems for placement equipment• Die shift compensation• Imaging with high depth of focus and high resolution• Local alignment LDI or scanner or stepper

• Yield ( Cost)• Suited materials and components• Optimized processes• Production experience learning curve

• Low k Polymers for RDL ( Performance)• Standard epoxy polymers are not sufficient for high performance RDL• Low k with low loss are essential for RF performance• Dry-film polymers offer the possibility for thick polymer layer

beneficial for RF

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FOPLP – Current Status

cost

performancef(L/S, pitch, no. dies, ….)

PL

WL

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Fraunhofer IZM FOPLP Industrial ConsortiumPhase I

cost


PL

WL

Validation of current FOPLP concerning equipment, material, performance and cost Differentiation against FOWLP

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Fraunhofer IZM FOPLP Industrial Consortium Phase II

cost


PL

WL

FOPLP enhancement with adapted/optimized equipment and materials Developments in direction of higher performance and lower cost

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Thanks for your attention!

Documents

Opportunities and Challenges for Fan-out Panel Level Packaging … · 2018-06-11 · Challenges for Panel Packaging assembly compression molding carrier preparation debonding redistri-bution