2 sanmina sn100c spanish
TRANSCRIPT
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 1/20
50μm
Copper laminate
Solder fillet
Solder resist
Sn-3.0Ag-0.5Cu
250°C, 3.3 seconds
Copper ErosionCopper Erosion During Wave Soldering
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 2/20
Sn-3.0Ag-0.5Cu
250°C, 3.3 seconds
50μm
Solder fillet
Copper laminate
Copper ErosionCopper Erosion During Wave Soldering
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 3/20
After 6 Passes Wave Soldering
105°C Preheat, 256°C Solder Temperature, 4 seconds contact time
Original Pad
18μm Copper
Sn-37Pb Sn-3.0Ag-0.5Cu SN100C
Copper ErosionCopper Erosion During Wave Soldering
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 4/20
After 6 Passes Wave Soldering
105°C Preheat, 256°C Solder Temperature, 4 seconds contact time
Original Pad
18μm Copper
Sn-37Pb Sn-3.0Ag-0.5Cu SN100C
Copper ErosionCopper Erosion During Wave Soldering
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 5/20
Copper
Erosion
(μm)
Number of Times
Wave Soldered
EXTENT of Cu EROSION on SOLDER SIDE PADS
as a FUNCTION of the NUMBER of TIMES WAVE SOLDERED
OSP Finish
Kyoden Ltd (Japan) Cu Erosion Study
Copper ErosionCopper Erosion During Wave Soldering
SAC305
SN100C
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 6/20
Copper
Erosion
(μm)
Number of Times
Wave Soldered
EXTENT of Cu EROSION on INSIDE WALL of THROUGH HOLES
as a FUNCTION of the NUMBER of TIMES WAVE SOLDERED
OSP Finish
Ref: Kyoden Ltd
Kyoden Ltd (Japan) Cu Erosion Study
Copper ErosionCopper Erosion During Wave Soldering
SAC305
SN100C
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 7/20
Repaired 5 times
Tip temperature: 35 ℃
Spec of the board
Pad depth： １６μｍ
Pad width : 0 165
ｍｍ
Distance between pads
： 0 165ｍｍ
SAC305
SN100C
Disappearance of
Cu tracks due to
erosion
Copper ErosionCopper Erosion During Rework
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 8/20
What has been the experience with SAC Alloys?
Stainless Steel Erosion
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 9/20
Stainless Steel Erosion
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 10/20
Stainless Steel Erosion
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 11/20
ENVIRONMENTAL IMPACT
Environmental Impact of Silver
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 12/20
Environmental Impact of Silver
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 13/20
Better
Worse
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 14/20
Environmental Impact of Silver
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 15/20
What is the electronics industrygoing to use
after SAC305?
SAC305
The real question…..
After ?
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 16/20
What is the alternative to Sn-Ag-Cu Lead-free Solders?
Sn-Ag- CuAdvantages of Sn-Cu
• Lowest raw material cost
• Low environmental impact
• Raw material readily available
•
Does not complicate recycling ofelectronic assemblies
• Simple so easy to manage
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 17/20
There is a convenient eutectic in
the Sn-Cu System
Cu6Sn5
Eutectic at 0.7Cu
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 18/20
Sn-0.7%Cu
Cooling Rate ~50C/sec
But the solidification behaviour is nearly as bad as SAC305
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 19/20
Sn-0.7Cu
Primary β-Sn
dendrites
Cooling rate ~ 5°C/sec
The Sn-0.7Cu alloy does not freeze as a eutectic
8/11/2019 2 Sanmina SN100c Spanish
http://slidepdf.com/reader/full/2-sanmina-sn100c-spanish 20/20
Primary β-Sn
Dendrites
EutecticMatrix
The Sn-0.7Cu alloy does not freeze as a eutectic