???SMT????????.

1
? ? ? ? ? ? ? ? ? ? ? ? ? --- ? ? ? ? ?
2
?????

1. ???SMT????????.

b.?????solder powder????Flux??????????.
c.??????????????,?????????PCB????.
d.????????SMD??.
e.??????????, ?SMD????PCB???????, ????, ????.
3
?????????
????????????, ???????? 1.????. 2. Flux?????.
???? Solder powder
?? Solder Paste
??? Flux.
4
????????
????????? a.?(Sb) b.?(Ag) c.?(Cu) d.?(Sb)
e.?(Bi) f.?(Zn) g.?(Pb) h.?(Fe) i.?(Al)
j.?(As) k.?(Cd) ???(Pb) ?(Cd)?Rohs?????
?(Pb)?????1000ppm ?(Cd) )?????100ppm
5
???????????????????
No Alloy Liquidus Temperature Remark
1 Sn63 - Pb37 183 Lead
2 Sn62 - Pb36 - Ag2 179 Lead
3 Sn96.5 - Ag 3.5 221 Lead-Free
4 Sn96.5 - Ag 3 - Cu0.5 217 Lead-Free
5 Sn89 - Zn8 - Bi3 194 Lead-Free
6
???????????
?? µm
Solder Power Type Solder Power Size Classification Remark
Type 2 25 63
Type 3 25 45 PAL
Type 4 25 38 Mostly
Type 5 15 32
Type 6 5 15
7
????
????????????,???????????????????????????/???????
?,???????????????,?????????(15µm??)??????????????
???? ???????????????????(Particle
size),??????????(Size Distribution)????,??????????
????????????
8
???????
??
???
???

• ??????????????????,?????????? (???)
  ???????,????????????????????????????????????????
  ?,?????????????????(Slump).

9
????????????????????
J-STD-005 ?? µm
Type ?????? ????? (??1???) ?????? (??80???) ????? (??10???)
1 160 150 15075 20
2 80 75 7545 20
3 50 45 4525 20
Type ?????? ????? (??1???) ?????? (??80???) ????? (??10???)
4 40 38 3820 20
5 30 25 2515 10
6 20 15 155 5
10
Flux????
?? Carrier Materials
?? Solvent
??? Flux
??? Activator
????? Theological Additive
11
Flux??????
No. Item Description
a ?? Carrier Material ???????????, ???????????.
b ?? Solvent ?????????????????
c ??? Activator -??(??) ???PCB????????,???????
d ????? Theological Additives ???????????????????????.
12
Flux???
No Type Content
a R Rosin, (Isopropyl Alcohol)
b RMA Rosin, Mildly Activated
c RA Rosin, Activated
d OA Organic Acid
e SA Synthetic, Activated

• Solder paste, solder wire use RMA type.

13
Solder Paste ????
b.
a.
c.
e.
d.
14
???????????
Classification Wetting Angle
Prefect wetting 0 ?lt 10
Excellent wetting 10 ?lt 20
Very good wetting 20 ?lt 30
Good wetting 30 ?lt 40
Adequate wetting 40 ?lt 55
Poor wetting 55 ?lt 70
Very poor wetting 70 ?lt 90
None wetting 90 ?
15
?????????(Phase Diagram)

• Sn-Ag-Cu IMC (Intermetallic Compounds)???????
• Cu6Sn5 Ag3Sn

16
????
???????????,??????????????????,????IMC??????????Cu
6Sn5,?????????????????,??????????? ?IMC??????????
??,???????????????????????????0.5-1.0µm??,??????IM
C?????????,????????????????,?????2µm???????,???Cu6
Sn5 ???IMC????????????????Cu3Sn.
?????????????????,??Cu3Sn??????????????,??????,IMC
????,??????????????????????? ??IMC??????????????,
??????????,????????????????????????????,??????????
???
17
SAC-IMC????
Ag3Sn
Cu6Sn5
Cu
18
SAC-IMC????
14µm??
1µm??
2µm

• IMC?? ????????.
• IMC?? ????????.
• ??IMC ???????????????sample profile.
• ??????????IMC??????

19
IMC????

• ???????Solder Join IMC????.

20
IMC???
21
????
?????????????????,???? ??????????????????????,
????????????????????,??????????????????????(??????
Thermal Shock)???,?????????????????,???????,??????
?????????????????????????????????????,????????????
????????????,?????????????????,?????????????????
?????????,?????????????????,??????????????,?????
???SMD??????? ??????,????????????? ????????????
? (???)??????????????????,???????????,????????????
?????,???????????? ,????????????????????????????
??,??????????????,??????????????,?????????????????
??????????????????????,???????????