JAXA MEWS23 JAXA 23rd Microelectronics Workshop

Electroless Ni/Pd/Au Plating Electroless Ni/Pd/Au Plating ect o ess / d/ u at gfor High Reliable Gold Wire Bonding with Electronic Devices for Space Applications

ect o ess / d/ u at gfor High Reliable Gold Wire Bonding with Electronic Devices for Space Applications p ppp pp

(1) Au Plating Combinations and Reliability(2) Au Grain Size and Crystal Growth(2) Au Grain Size and Crystal Growth(3) Diffusion of Under-plated Metal onto Au surface(4) Wire Bonding Reliability Ranking of Au Plating

Yukihisa Hiroyama

(4) Wire Bonding Reliability Ranking of Au Plating

Hitachi Chemical Co., Ltd.

JAXA MEWS23 11

Structure of BGA AssemblyStructure of BGA Assembly

Gold WireDie Bonding

MaterialSemiconductor

Chip

Molding

Gold Wire Chip

WireWire MoldingMaterial

P k S b t t

WireWireBondingBonding

Solder Ball

Solder Solder JointJoint

Package Substrate

BallPrinted Circuit Board

JointJoint

JAXA MEWS23 Wire BondingWire Bonding

22Wire BondingWire Bonding

Gold WireAluminum ElectrodeCopper

Line

LSILine Resist

LSI

Die Bonding Material G ld Pl t dDie Bonding Material Gold PlatedTerminalPackage Substrate

JAXA MEWS23

Solder Ball JointSolder Ball Joint33

Solder Ball JointSolder Ball Joint

Package SubstrateCopper Pad Package SubstrateCopper Pad

Solder Ball Gold Plated Terminal

Solder BallResist

JAXA MEWS23 44

Characterization of Gold PlatingCharacterization of Gold PlatingE’less Ni/Au(ENIGEG)(5/0 5µm)

E’lyticNi/Au(5/0 5µm)

ItemE’less Ni/Pd/Au(ENEPIGEG)(5/0 5/0 5µm)

Wire Bondability OK OK OK(5/0.5µm)(5/0.5µm) (5/0.5/0.5µm)

Wire Bondabilityafter Aging*Wi B d bilit

OK NG OKWire Bondabilityafter Aging*and Plasma**

OK OK OK

Solder Joint Reliability OK NG OK

* Aging : 150ºC, 50 hours ** Plasma : O2 plasma

JAXA MEWS23

G ld Pl i C bi i i hG ld Pl i C bi i i h55

Gold Plating Combination withE’less and E’lytic Processes

Gold Plating Combination withE’less and E’lytic Processesyy

Gold Plating Process Thickness (µm)ENEPIGEG (Ni/Pd/Au)ENEPIG (Ni/Pd/IG)

5/0.5/0.55/0.5/0.05

Gold Plating Process Thickness (µm)

ENEPIG (Ni/Pd/IG)ENIGEG (Ni/Au)Ni(SB-Watt)/E’lytic Au

5/0.5 5/0.5

Ni(B-Watt)/E’lytic Au Ni(B-Sulf)/E’lytic AuNi(SB Watt)/IGEG

5/0.5 5/0.5 5/0 5Ni(SB-Watt)/IGEG

EN/E’lytic AuCu/E’lytic Au

5/0.5 5/0.5 0.5 Cu/ yt c u

JAXA MEWS23 66

Wire Bonding Reliabilityof Gold Plating Combinations

Wire Bonding Reliabilityof Gold Plating Combinations

14

of Gold Plating Combinationsof Gold Plating Combinations

10

12

th (g

f)

As Gold PlatingHeat Treatment

6

8

l Str

engt Heat-Treatment

(150oC, 3h)

2

4

Pull

0

EPIG

EGPd

/Au)

NEP

IGPd

/IG)

NIG

EGN

i/Au)

B-W

att)

ic A

u

B-W

att)

ytic

Au

B-S

ulf.)

ytic

Au

B-W

att)

G ytic

Au

ytic

Au

ENE

(Ni/P EN (Ni/ EN (N

Ni(S

B/E

’lyt

Ni( B

/E’ly

Ni(B

/E’ly

Ni(S

B/IG

EG

EN/E

'ly

Cu/

E'ly

JAXA MEWS23

Surface Morphology andSurface Morphology and77

Surface Morphology andFIB/SIM Cross Section

Surface Morphology andFIB/SIM Cross Section

ENIGEG (Ni/Au)ENEPIG (Ni/Pd/IG)ENEPIGEG (Ni/Pd/Au)

rfac

eho

logy

Sur

Mor

phM tio

n AuAu AuAuPdPdAuAu

FIB

/SIM

oss

Sect PdPd

PdPd

Cro NiNi NiNiNiNi 1 µm1 µm 1 µm1 µm1 µm1 µm

JAXA MEWS23

Surface Morphology andSurface Morphology and88

Surface Morphology andFIB/SIM Cross Section

Surface Morphology andFIB/SIM Cross Section

Ni(B-Sulf.)/AuNi(B-Watt)/AuNi(SB-Watt)/Au

rfac

eho

logy

Sur

Mor

phM tio

n AuAu AuAuAuAu

FIB

/SIM

oss

Sect

Cro NiNi NiNiNiNi 1 µm1 µm 1 µ m1 µ m1 µm1 µm

JAXA MEWS23

Surface Morphology andSurface Morphology and99

Surface Morphology andFIB/SIM Cross Section

Surface Morphology andFIB/SIM Cross Section

Cu/E’lytic AuEN/E’lytic AuNi(SB-Watt)/IGEG

rfac

eho

logy

Sur

Mor

phM tio

n

AuAuAuAuAuAu

FIB

/SIM

oss

Sect

Cro NiNi CuCuNiNi 1 µm1 µm 1 µm1 µm1 µm1 µm

JAXA MEWS23 1010

EBSP Mapping of GoldEBSP Mapping of GoldENIGEG(Ni/Au)

ENEPIGEG(Ni/Pd/Au) Ni(B-Watt)/E’lytic AuNi(SB-Watt)/E’lytic Au

0.18 m2※

0.06 m2※ 0 03 m2※ 0.03 m2※

Cu/E’lytic AuNi(SB-Watt)/IGEG EN/E’lytic AuNi(B-Sulf.)/E’lytic Au

0.06 m 0.03 m2※ 0.03 m

111 0 50 35 2※2※001 101

0.5 m0.23 m2※ 0.35 m2※0.03 m2※

0.03 m2※

※ : Average cross-sectional area of gold grain

EBSP: Electron Back Scattering Pattern

JAXA MEWS23 EBSP MappingEBSP Mapping

1111EBSP Mapping

Ni(SB-Watt)/IGEGEBSP Mapping

Ni(SB-Watt)/IGEGNi AuAu

Au

NiNi

Cu

CuCu 1 m

All Au Ni Cu EDXAll Au Ni CuEnergy Dispersion X-ray Spectrometry

E’lytic Ni(SB-Watt)/IGEGEBSP: Electron Back Scattering Profile

EDX

JAXA MEWS23

EBSP MappingEBSP Mapping1212

EBSP MappingENEPIGEG (Ni/Pd/Au)

EBSP MappingENEPIGEG (Ni/Pd/Au)

Electroless Ni/Electroless Pd/ Immersion Au/Electroless Au

Pd AuAu

AuPdPd

0.5 m

All Au Pd EDXEnergy Dispersion X-ray Spectrometry

ENEPIGEGEBSP: Electron Back Scattering Profile

JAXA MEWS23 1313

EBSP MappingCu/E’lytic Au

EBSP MappingCu/E’lytic AuCu/E lytic AuCu/E lytic Au

Copper/Electrolytic Au

CuA

Copper/Electrolytic Au

Au

Au

Au

CuCu 0.5 m

Au

All Au CuEnergy Dispersion X ray Spectrometry

Cu/E’lytic Au

EDX

X-ray SpectrometryEBSP: Electron Back Scattering Profile

JAXA MEWS23

Thermal Diffusion BehaviorThermal Diffusion Behavior1414

Thermal Diffusion Behaviorof Under-plated Metal

Thermal Diffusion Behaviorof Under-plated Metal

By XPS Analysis(X-ray Photoelectron Spectrometry)

Gold PlatingProcess Cu PdNi Cu PdNiCu PdNi

3 hours 25 hours 50 hours

ENEPIGEG (Ni/Pd/Au)

ENEPIG (Ni/Pd/IG)

ENIGEG (Ni/Au)

---

-1.5-

--

5.8

---

-3.0-

--

12.2

---

-1.0-

--

2.6ENIGEG (Ni/Au)

Ni(SB-Watt)/Au Ni(B-Watt)/Au Ni(B S lf)/A

---

--

5.83.45.3

--

--

12.25.4

11.9--

--

2.61.83.8

Ni(B-Sulf)/AuNi(SB-Watt)/IGEGEN/E’lytic Au

---

---

5.72.37.4

---

---

11.64.1

11.8

---

---

5.01.66.1y

Cu/E’lytic Au 14.5 -- 15.7 --14.2 --Heat Treatment: 150ºCHeat Treatment: 150ºCAtomic%Atomic%Atomic%Atomic%

JAXA MEWS23

Nickel DistributionNickel Distribution1515

Nickel Distribution over Gold Plating Surface

Nickel Distribution over Gold Plating Surface

By AES Analysis(Auger Electron Spectrometry)

ENIGEG (Electroless Ni/Au) : 5µm/0.5µm Heat Treatment: 150ºC, 50hHeat Treatment: 150ºC, 50h

Ni

Au

JAXA MEWS23

G i B d Diff i dG i B d Diff i d1616

Grain Boundary Diffusion andBulk Diffusion (Interdiffusion)Grain Boundary Diffusion andBulk Diffusion (Interdiffusion)( )( )

Contamination on Gold Surface

GoldGold Grain

Gold

Grain BoundaryGrain BoundaryGrain BoundaryGrain Boundary

Grain BoundaryGrain BoundaryDiffusionDiffusion

Bulk DiffusionBulk Diffusion(Interdiffusion)(Interdiffusion)

Under Plated MetalUnder PlatedMetal Grain

(Interdiffusion)(Interdiffusion)

JAXA MEWS23

Model of Grain Structure andModel of Grain Structure and1717

Model of Grain Structure and Diffusion on ENEPIGEG

Model of Grain Structure and Diffusion on ENEPIGEG

IGEG

ENEPIGEG

IGEGIGEG

ENEPIGEG(Electroless Ni/Pd/Au)

IGEGIGEG

EPEP EP

ENEN ENFIB/SIM Analytical Result

Grain Boundary DiffusionGrain Boundary Diffusion

FIB/SIM Analytical Result

JAXA MEWS23 1818

Model of Grain Structure andModel of Grain Structure andModel of Grain Structure and Diffusion on Ni(SB-Watt)/AuModel of Grain Structure and Diffusion on Ni(SB-Watt)/Au

E’lytic Au or IGEGE’lytic AuE’lytic Au NiO

Ni(SB-Watt)Ni(SB-Watt)IGEG (E’less Au)IGEG (E’less Au)

Ni(SB W tt)

Ni(SB-Watt)Ni(SB-Watt)

Ni(SB-Watt)

( )( )

Grain Boundary DiffusionGrain Boundary DiffusionFIB/SIM Analytical Result

JAXA MEWS23

Model of Grain Structure andModel of Grain Structure and1919

Model of Grain Structure and Diffusion on B-Ni/Au and EN/Au

Model of Grain Structure and Diffusion on B-Ni/Au and EN/Au

IGEGIGEGIGEG or E’lytic AuNiOE’less Ni/AuE’less Ni/Au

ENEN

ENENE’lytic AuE’lytic AuENEN

E’lytic AuE’lytic Au Bright Ni and EN

Ni(B-Watt)Ni(B-Watt) E’lytic Bright Ni Plating

Grain Boundary DiffusionGrain Boundary Diffusion

(1) Bright Watt(2) Bright SulfamateFIB/SIM Analytical Result

JAXA MEWS23

Model of Grain Structure andModel of Grain Structure and2020

Model of Grain Structure and Diffusion on ENEPIG

Model of Grain Structure and Diffusion on ENEPIG

PdIG

OrganicContaminationENEPIG

Pd

IGIG

(Electroless Ni/Pd/IG)

EPEPEPIGIG

ENENEN

FIB/SIM Analytical ResultFIB/SIM Analytical Result

Grain Boundary DiffusionGrain Boundary Diffusion

JAXA MEWS23

Model of Grain Structure andModel of Grain Structure and2121

Model of Grain Structure and Diffusion on Cu/E’lytic Au

Model of Grain Structure and Diffusion on Cu/E’lytic Au

E’lytic AuCuO (Bulk)CuO (Grain boundary)

E’lytic AuE’lytic Au

CuCuCuCu

Interdiffusion (Bulk Diffusion)Grain Boundary DiffusionInterdiffusion (Bulk Diffusion)Grain Boundary Diffusion

FIB/SIM Analytical Result

JAXA MEWS23

Estimated Ranking ofEstimated Ranking of2222

Estimated Ranking ofWire Bonding Reliability

Estimated Ranking ofWire Bonding Reliability

ENEPIGEG, Ni(SB-Watt)/IGEGGood

ng y

and Ni(SB-Watt)/E’lytic Au

Bon

din

abili

ty

ENEPIG, Ni(B-Watt)/E’lytic AuAnd Ni(B-Sulf.)/E’lytic Au

Wire

BR

elia And Ni(B Sulf.)/E lytic Au

ENIGEG, EN/E’lytic Au

W

Poor Cu/E’lytic Au

JAXA MEWS23

SS2323

SummarySummary(1) Th li bilit f ENEPIGEG (E’l(1) The reliability of ENEPIGEG (E’less

Ni/Pd/Au) and E’lytic Ni (SB-Watt)/IGEGi l t t th t f E’l ti Ni (SBwas equivalent to that of E’lytic Ni (SB-

Watt)/E’lytic Au after the heat treatment.(2) Th li bilit d d d th diff i(2) The reliability depended on the diffusion

behavior of the under-plated metals andth i i f th ld d itthe grain size of the gold deposit.

(3) The grain size of Au plating coordinatedith th i i f th d l t dwith the grain size of the under-plated

metals as the epitaxial crystal growth.