status and perspectives of metallization ......advanced metallization line configuration 6 back ag...

Applied Materials Confidential

STATUS AND

PERSPECTIVES OF

METALLIZATION

TECHNOLOGIES FOR HVM Marco Galiazzo

Process Eng Manager

| Applied Materials External Use

Agenda

c-Si Technology Roadmap

BCS Metallization Roadmap

Advanced Line Configuration

► Bi-PERC+SE

► DP/Knotless

► Shingling

Conclusion


Metallization technology key to control

performances

c-Si Technology Roadmap

p-multi BSF up to 20.5% CE

p-mono BSF Up to 21.5% CE

Esa

tto

AO

I, F

LD

P, m

etr

olo

gy,

In

du

str

y 4

.0

p-multi PERC up to 21.5% CE

p-mono PERC up to 22.5% CE

Esa

tto

SE

m,

Se

lective

BS

F

LE

D F

lash

er

n-PERT/PERL up to 23% CE

Cu

sto

m E

sa

tto

Cu

sto

m a

uto

ma

tio

n

Heterojunction up to 24.5% CE

IBC up to 25% CE P

rint

Dry

an

d c

ure

Fu

ll cu

sto

m

so

lutio

ns

Un

iqu

e e

nab

lin

g B

accin

i te

ch

no

log

ies

Tool extendibility requirements

3


FLDP Metallization Roadmap

4

FLDP at least -5um over SP in mass production, Aspect Ratio >0.5

FLDP

Mesh 325/16

360/16

380/14

440/13 11um wire

25 um opening

8 um opening

Screen images courtesy of Murakami

Ref: itrpv.net/Reports/Downloads

| Applied Materials External Use 5

FLDP Mass Production Data - Jinergy

Processing conditions

Cell type Cz-Si PERC

Screen opening 22 + 22 um

Mesh type 380-14

Finger width 35-38 um

Paste type A + A

Printing speed 300 mm/s

Flooding speed 800 mm/s

Electroluminescence <5 interruptions

FLDP providing <40 um finger width in mass production, no EL defects

Data used with customer permission


Advanced Metallization Line Configuration

6

Back Ag Back Al Front 1st Front 2nd

Edge

±25 µm Pattern ±12.5 µm

Pattern ±12.5 µm

Pattern ±12.5 µm

Shingling

Bi-PERC SE FLDP/DuP

Metal

Process

Alignm.

4 items configuration commonly adopted, requirement for high precision for all steps

1 2 3 4


Power Up +10% power from same module size

Fully compatible with all cell technologies

Energy yield Lower operating temperature means better performance ratio

Work with bifacial modules

Reliability No residual stress between metal and Si

Better aesthetics Premium for residential applications

7

Shingled Modules – Value Drivers Full area utilization

No ohmic losses Improved reliability

Shading Ohmic losses Gaps

Cracks Fatigue

Wöhrle, N. et al., Photovoltaics International 36, 2017


Alignment for Shingling - Print

8

Shingling needs precise edge alignment for both front and rear metallization along print direction!

Y

X

±25 µ

m

±25 µ

m

±7.5

md

eg

OK NOK

ECA

Shingling cell layout

1 2 3

Offset measurement printing vs edge


Alignment for Bifacial PERC – Print

laser

pri

nt

40 µm 240 µm

Bi-PERC requires pattern alignment on laser lines, reducing cell cost and increasing module yield

Align on laser lines

±12.5

µm

±5 m

deg

2

Y

X

Offset measurement Al print vs laser

Bi-PERC advantages:

• 60-70% bifaciality

• Low Al consumption

(<0.5g/cell)

Disadvantages:

• Decrease front

efficiency

Dullweber et al, 31st European Photovoltaic Solar Energy Conference, Hamburg, 2015


Alignment for Selective Emitter - Print

10

Used with Customer permission Edge align Pattern align

% of cells with CE <21% 9.36% 0.08%

% of cells with CE <20.8% 1.59% 0 %

% of cells with CE <20.5% 0.28% 0 %

3

Pattern alignment allowing 0.1% CE gain over edge, no low efficiency cells tail


FLDP for Shingling – Print

11

31.2 mm

Shingling 1/5 cell bb

bb

4 busbars cell

19.5 mm

bb

bb

High A/R fingers achieved in FLDP needed for shingling layout to reduce resistive losses

Lot Width

[µm]

Height

[µm]

A/R Weight

[mg]

FLDP

25um

36 21 0.58 131

SP 35um 45 18 0.4 120

+0.17% eff

SP EL

4 interrupts

FLDP EL

0 interrupts

4


Knotless Dual Printing - Print

12

SP

Screens

DuP

Knotless

FLDP

Screens

Finger profile Average Excellent Good

Min linewidth 45 µm 40 µm 35 µm

Efficiency gain Ref. +0.15% +0.2%

Screen lifetime 40k 30k (100k BB) 50k

Screen price Low High (low BB) High (2x)

Paste cons. Mid Low (on BB) Mid

Applicable to SE Yes No Yes

EL Yield Low Mid High

CoO Mid Low Low

Knotless is a promising approach (in DuP) some concerns exist on EL and image deformation

4

Knotless finger morphology ‘No wire’ knotless

Knotless screen: 100um deformation

FLDP screen: stable image


Advanced Line Results

Test results

• 60 cells equivalent modules

• Reference PERC 290W

• Average power for shingling 314W, max 323W

Advanced Line can deliver 325W shingled modules, TC800 reliability ok

initial

TC400

TC800


Conclusion

Cell technology is constantly evolving: PERC, bi-PERC, SE+DP, knotless being

introduced to increase efficiency

FLDP targeting <35um lines in mass production next year

Module technology is (finally) evolving, bringing in new requirements

Metallization process is becoming more critical for all technologies

► Precise edge alignment front/rear

► Pattern alignment for bi-PERC and SE (fiducial, laser lines)

► FLDP for high A/R in shingling

Screen printing is still mainstream process...and has a long and bright future!

14

Thank you!

status and perspectives of metallization ......advanced metallization line configuration 6 back ag...

Documents