ALPHA® SACX PLUS™ 0307 HASL

an Alent plc Company

ALPHA® SACX

PLUS™ 0307

HASL Product Guide

the product:

Engineered to deliver

uniform thickness and

flatness during high speed

processing while

contributing to improved

assembly reliability

Highly Confidential and Privileged Information of Alpha an Alent plc Company

Lead-Free HASL

• Alpha has developed a low cost, high reliability Lead-Free

alloy that is suitable for the HASL process

• Alloy is part of the SACX family

• The alloy minimizes copper dissolution and delivers vary flat

pads even for the smallest components

• Flatter pads than traditional Tin Lead.

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Key attributes of SACX Plus™ 0307 HASL

• Alloy contains all the primary constituents of standard SACX

• Exceptional wetting performance

• Low drossing

• High mechanical reliability

• Low Ag (low cost)

• Requires lower overall processing temperatures

• Higher Nickel content than standard SACX

• Decreases copper erosion rate

• Improves joint appearance slightly

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Reliability Density / Specific Gravity

Thermal Conductivity

Coefficient of Thermal

Expansion

Tensile Strength (M-Pa)

Elongation %

Hardness

Creep Strength (time to failure)

Stress Testing – joint strength

Stress Testing - thermal cycling

Tin Whiskers

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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.


Why do silver bearing alloys exhibit high

thermal fatigue resistance?

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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 stress Sn-Cu-Ni sample

High Cycle Fatigue by Gunther Grossman

Key Considerations


Reliability data

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Key Considerations

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


Dross Reduction

• All SACX® alloys, including SACX® PLUS™ HASL,

contain an additive that reduces drossing rates

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Huawei Technical Study

Note: Alloy C is SACX®0807 – this alloy has the same

amount of antioxidant as SACX® HASL


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“In our test, SACX HASL exhibits a slightly better copper

dissolution rate than SN100C” – Serigroup - Belluno, Italy

3rd Party Copper Dissolution Test Results


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.

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• They have been using

SACX® 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


Case Study 1 PENTAGAL Chemie und Maschinenbau GmbH Bochum, Germany

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HASL Equipment and Settings

PENTA AUTOMATIC® Vertical Leveling System

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Test Conditions


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.”

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Other Findings…

• Uneven copper surfaces were coated evenly with SACX®

HASL alloy. Min thickness at the knee 2 µm.

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> 2 µm


Other Findings…

• Maximum copper erosion measured - 4µm.

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Maximum erosion observed - 4µm


Other Findings…

• Copper levels are easy

to maintain by daily

precipitation of Cu6Sn5

IMC

• Reduce the temperature

to just under liquidus

and remove the crystals

that precipitate.

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Case Study 2

Circuit Engineering Marketing Company (CEMCO) Hampshire, UK

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HASL Equipment and Settings

CEMCO Quicksilver Vertical

Leveling System

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• 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


Flatness of Pads

• Test conducted to measure the flatness of pads.

• Tests show that the SACX Plus 0307 HASL alloy has

overall greater flatness than Sn/Pb.

• SACX suitable as a drop in replacement for current

Sn/Pb process.

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SACX HASL Sn63/Pb37


Front ‘Vertical’ Features Measured.

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Front ‘Vertical’ Features Analysis

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• Much flatter deposits

than SnPb (2-3 µm vs. >7-

10 µm w/ SnPb)

• Good Thickness

Control

• Low Std. Deviation

• Low Range


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

kn

ess

( m

icro

ns)

Cu

Solder

IMC

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Additional flatness

data on different test

board


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SACX® HASL Cosmetics vs. SN100C

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

Both alloys produce

smooth, complete finishes

at solder pot temperatures

of 265º C and higher.


Other Performance Attributes

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Spread 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®

HASL exhibits slightly faster wetting

speed than the SN100C alloy


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

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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

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For more information on Alpha

products please visit:

www.Alpha.Alent.com

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ALPHA® SACX PLUS™ 0307 HASL

Technology

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