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PRIVILEGED AND CONFIDENTIAL MATERIALS
ALPHA®
SACX™ 0307 HASL
Product Guide
the product:Engineered to deliver uniform thickness and flatness during high speed processing while contributing to improved assembly reliability
2 PRIVILEGED AND CONFIDENTIAL MATERIALS
Lead-Free HASL• Cookson Electronics have developed a low cost, high
reliability Lead-Free alloy that is suitable for the HASL process• Alloy is part of the SACX™ Plus family
• The alloy minimizes copper dissolution and delivers vary flat pads even for the smallest components
• Flatter pads than traditional Tin Lead.
3 PRIVILEGED AND CONFIDENTIAL MATERIALS
Key attributes of SACX™ 0307 HASL• Alloy contains all the primary
constituents of standard SACX™Plus
• Exceptional wetting performance
• Low drossing• High mechanical reliability• Low Ag (low cost)
• Requires lower overall processing temperatures
• Higher Nickel content than standard SACX™Plus
• Decreases copper erosion rate
• Improves joint appearance slightly
4 PRIVILEGED AND CONFIDENTIAL MATERIALS
Reliability
Tin Whiskers
Stress Testing - thermal cycling
Stress Testing – joint strength
Creep Strength (time to failure)
HardnessElongation %
Tensile Strength (M-Pa)
Coefficient of Thermal Expansion
Thermal ConductivityDensity / Specific Gravity
Key Considerations
•Small amounts of Bismuth (<3%) improves the fatigue resistance of Lead-Free solder alloys. This is due to the solid solubility of Bismuth in Tin that results in a hardening of the alloy.
•Silver improves the fatigue resistance of Lead-Free alloys as it forms IMC Ag3Sn with the tin, these hard platelets increase the fatigue resistance.
5 PRIVILEGED AND CONFIDENTIAL MATERIALS
Why do silver bearing alloys exhibit high thermal fatigue resistance?
High Ag alloys contain more Ag3Sn intermetallic compound (IMC) in the bulk solder matrix resulting in greater mechanical strength and higher resistance to stress during temperature cycling
The bulk solder matrix of Ag-free alloys (ie. SN100C) are weaker
and less resistant to stressSn-Cu-Ni sample
High Cycle Fatigue by Gunther Grossman
Key Considerations
6 PRIVILEGED AND CONFIDENTIAL MATERIALS
Reliability dataKey Considerations
Silver contributes to alloy strength while also helping to keep it ductile – improving it’s ability to absorb and recover
from mechanical stress
Silver contributes to alloy strength while also helping to keep it ductile – improving it’s ability to absorb and recover
from mechanical stress
The Ag3Sn platelets also make the alloy hard
Vibration test, High Cycle Fatigue by Gunther Grossman
Charpy Impact Test
7 PRIVILEGED AND CONFIDENTIAL MATERIALS
Dross Reduction• All SACX® alloys, including SACX™ 0307 HASL,
contain an additive that reduces drossing rates
Huawei Technical Study
Note: Alloy C is SACX™ Plus 0807 – this alloy has the same amount of antioxidant as SACX™ 0307 HASL
8 PRIVILEGED AND CONFIDENTIAL MATERIALS
“In our test, SACX™ Plus 0307 HASL exhibits a slightly better copper dissolution rate than SN100C” – Serigroup -Belluno, Italy
3rd Party Copper Dissolution Test Results
9 PRIVILEGED AND CONFIDENTIAL MATERIALS
SACX™ Plus 0307 HASL• This product has been in the market since early 2006. • There are nearly 20 customers that have been using SACX® HASL
for at least one year.
• They have been using SACX™ Plus 0307 HASL in their machines since the middle of 2006 (they offer sub-contract services for the finishing of boards)• They have released reports on the performance of the alloy.
We have been working closely with leading HASL machine manufacturers
10 PRIVILEGED AND CONFIDENTIAL MATERIALS
Case Study 1 PENTAGAL Chemie und Maschinenbau GmbH
Bochum, Germany
11 PRIVILEGED AND CONFIDENTIAL MATERIALS
HASL Equipment and SettingsPENTA AUTOMATIC® Vertical Leveling System
Test Conditions
12 PRIVILEGED AND CONFIDENTIAL MATERIALS
SACX™ Plus 0307 HASL
Evaluation Findings“This alloy was very easy to
use and showed a remarkable wide process window concerning process temperature and alloy composition. Even at the lower end of the temperature window the leveling and brightness of the alloy was very satisfactory.”
“The good wetting performance of this solder alloy resulted in very smooth surfaces which gave a semi glossy appearance.”
13 PRIVILEGED AND CONFIDENTIAL MATERIALS
Other Findings…• Uneven copper surfaces were coated evenly
with SACX™ Plus 0307 HASL alloy. Min thickness at the knee 2 µm.
> 2 µm
14 PRIVILEGED AND CONFIDENTIAL MATERIALS
• Maximum copper erosion measured - 4µm.
Other Findings…
Maximum erosion observed - 4µm
15 PRIVILEGED AND CONFIDENTIAL MATERIALS
• Copper levels are easy to maintain by daily precipitation of Cu6Sn5IMC
• Reduce the temperature to just under liquidus and remove the crystals that precipitate.
Other Findings…
16 PRIVILEGED AND CONFIDENTIAL MATERIALS
Case Study 2 Circuit Engineering Marketing Company (CEMCO)
Hampshire, UK
17 PRIVILEGED AND CONFIDENTIAL MATERIALS
HASL Equipment and SettingsCEMCO Quicksilver Vertical
Leveling System
• Bath temperature: 260°C• Immersion time: 4 seconds• Air Knife pressure: 30 PSI on the
front : 30 PSI on the rear.• Air knife temperature: 280°C• Immersion speed: 751 mm/s• Remove speed: 547 mm/s
18 PRIVILEGED AND CONFIDENTIAL MATERIALS
Flatness of Pads• Test conducted to measure the flatness of pads.• Tests show that the SACX HASL alloy has overall
greater flatness than Sn/Pb.• SACX suitable as a drop in replacement for current
Sn/Pb process.
SACX HASL Sn63/Pb37
19 PRIVILEGED AND CONFIDENTIAL MATERIALS
Front ‘Vertical’ Features Measured.
20 PRIVILEGED AND CONFIDENTIAL MATERIALS
Front ‘Vertical’ Features Analysis
• Much flatter deposits than SnPb (2-3 µm vs. >7-10 µm w/ SnPb)
• Good Thickness Control
• Low Std. Deviation
• Low Range
21 PRIVILEGED AND CONFIDENTIAL MATERIALS
Average comparison of all locations. Solder deposits
average under 6 µm.
Comparison of the thickness with all the locations
0
5
10
15
20
25
30
35
40
QFP SMT 1 SMT2 PTH
thic
knes
s ( m
icro
ns)
Cu
Solder
IMC
Additional flatness data on different test
board
22 PRIVILEGED AND CONFIDENTIAL MATERIALS
SACX™ Plus 0307HASL Cosmetics vs. SN100C
At solder pot temperatures below 265ºC
SN100C exhibits
dewetting and a grainy
surface finish
At solder pot temperatures below 265ºC
SN100C exhibits
dewetting and a grainy
surface finish
260º C
255º C
255º C
260º C
SACX® HASL pad coverage is complete and finishes are smooth
at lower pot temperatures
SACX® HASL pad coverage is complete and finishes are smooth
at lower pot temperatures
Both alloys produce smooth, complete finishes at solder pot temperatures
of 265º C and higher.
23 PRIVILEGED AND CONFIDENTIAL MATERIALS
Other Performance AttributesSpread Testing
Conclusion – Similar spreading behavior between the two alloys
Print SAC305 based no-clean solder paste on HASL pads
Wetting Speed and Force
Conclusion – In this test SACX™
Plus 0307 HASL exhibits slightly faster wetting speed than the SN100C alloy
24 PRIVILEGED AND CONFIDENTIAL MATERIALS
General Customer Value Propositions for all Alpha Products
• Consistent Product Performance Globally• Manufacturing Lot Trace-ability• High Reliability Products• Access to Application Laboratories• Solder Scrap Value Recovery• Global OEM / EMS Company
Relationships
25 PRIVILEGED AND CONFIDENTIAL MATERIALS
SACX™Plus 0307 HASL Potential Sources of Value
• Improved Reliability– Contributes to increased Drop Shock Resistance vs Higher Ag alloys– Contributes to increased Thermal Fatigue Resistance vs. Ag-free SnCu
alloys (ie SN100C)– Dramatically better Cu Dissolution rates vs. SAC 305
• Higher Yields– Better wetting performance vs. Ag-free SnCu alloys (ie SN100C)
delivering lower SMD related defects and better hole fill.– Uniform, flat pads for improved paste printing and lower SMD related
defects• Reduced Cost of Ownership
– Reduced dross rates vs SAC305 and many other low-Ag and Ag-free alloys
– Compatible with most popular Pb-free alloys– Lower processing temperatures than Ag-free SnCu alloys– Lower cost of metals versus industry standard SAC 305– Long shelf life (1-2 yrs) of plated assemblies