BGA焊接缺陷分析-白蓉生

Part
27 BG A P CB IMC EN IG BG A PCB Root Cause BGA F ocused Ion Beam ENIG FIB
Sn63 PCB EN I G Sn63 N i 3S n 4 N i 3S n 4 IMC
Pb37
FIB

1
2
3
4
BGA
ENIG
1
5000 IMC
2
F IB 7-9%by w t

ENIG AuSn2 AuSn4 4500 IMC F IB IMC N i 3S n 4 EN
AuSn
1
IMC Mass
Ni3Sn4 Thermal
3 Gold Embrittlement
Au
19.3
N i 3S n 4 AuSn AuSn2 EN IG C u 6S n 5
IMC

1
E NIG FIB Bond Stre ngth AuSn AuSn AuSn
IMC
N i 3S n 4
1
IMC IMC
BGA N i 3S n 4 BGA IMC
EN I G
P CB

BGA 200 E N IG BG A
1
BGA
Reflow
Ni3Sn4

27
28 Substrates I-Ag I-Sn I-S OSP OSP HASL I-Au HASL
I-Ag
I-Au
Reflow Soldering
Solder
OSP Treated
Solder
Mask
Solder Paste
Mask
Residue of flux and some thicker OSP's expected
FET A g 3S n
Sn63 Sn62 Pb36 Ag2
Pb37 FE

PCB A g 3 Sn Pla te IMC
IMC Spreading IMC Contact Angle IMC
1

28
Interfacial Microvoiding
O utg ssing A g 3S n Di ss olution de ndrite IMC IMC
Build up HDI RCC Microvia HDI
1
2
3
5 4

HDI 3+4+3 XY
1+4+1B 2+4+2B 2+4+1 RCC
Td
T 288
2-CTE
Voiding BGA Via in P ad
Substrates via 15-18

J-S T D-001D
2005.2 25
Table 7-14 N ote 1 Voiding
X -ra y
TBBA RoS H Halogen F ree PCB TBBA