ALPHA® OM-353 Solder Paste

Technical Data

No-Clean, Low-Silver, Lead-Free, Zero-Halogen, ROL0, Ultra-Fine Feature Printing & Air Reflow Solder Paste

Description

ALPHA OM-353 is a low-silver SAC305 solder paste designed for ultra-fine feature applications using Type 5 (15 to 25 µm) powder. It exhibits excellent printing performance on pad sizes as small as 180 µm, tested with 60° squeegee at 50 mm/s, release at 2 mm/s, and 0.18 N/m pressure. ALPHA OM-353 is also available in Type 4 (20 to 38 µm) powder.

ALPHA OM-353 has demonstrated low levels of Non-Wet Open (NWO), Head-in-Pillow (HiP), and residue spread. Additional testing shows minimal flux wicking.

Features & Benefits

Long Stencil Life: Tested up to 80 hours per Alpha internal procedures, maintaining consistent performance in warm/humid climates while reducing printing fluctuations and paste drying.
High Tack Life: Ensures high placement yields and good self-alignment.
Wide Reflow Profile Window: Supports complex, high-density PWB assemblies in air or nitrogen using high soak (170-180°C) profiles.

Excellent Coalescence:

Powder Size	Reflow Profile (Air)	Alloy
Powder Size	Reflow Profile (Air)	SAC305	SACX 0307
T5	Low Soak	160 µm	170 µm
T5	High Soak	160 µm	170 µm

Reduced Defects: Minimizes Mid-Chip Solder Balling (MCSB) and Head-in-Pillow (HiP), maximizing first-pass yield.
Aesthetic Residue: Clean solder joint and residue appearance even after long/high heat soak.
Low Voiding: Meets IPC-7095 Class 3 requirements for BGA.
Halogen-Free: Zero-Halogen, no intentionally added halogens.
Reliability: Passes JIS copper corrosion and all standard SIR tests.
Compliance: Meets RoHS, TSCA, EINECS, and Halogen-Free requirements.
Low-Silver Alloys Available.

Product Information

Alloy: SAC305, SAC105, Sn96.5Ag3.5, SACX Plus 0307, Innolot

Powder Size: Type 4 (20-38 µm), Type 5 (15-25 µm)

Packaging: 500g Jars, 6” and 12” Cartridges

Flux Gel: Available in 10cc and 30cc syringes for rework

Lead-Free: RoHS Directive EU/2015/863; Amending Annex II of 2011/65/EU

Application Guidelines

Designed for standard and fine-pitch stencil printing at speeds between 25 mm/sec and 150 mm/sec. Recommended stencil thickness is 0.100 - 0.150 mm (4 - 6 mil), especially when used with ALPHA stencils. Squeegee pressure should be 0.21 - 0.36 kg/cm (1.25 - 2.0 lb/inch) depending on speed. Higher speeds require higher pressure. The reflow window ensures high yields and minimal rework.

Technical Specifications

Category	Results	Procedure/Notes
Chemical Properties
Flux Classification	ROL0	IPC J-STD-004B
Halide Content	Halide-Free ( I.C.), < 0.05%	IPC J-STD-004B
Fluoride Spot Test	Pass, No Fluoride present	JIS Z 3197:1999 8.1.4.2.4
Halogen Content	Pass, Zero-Halogen - No intentionally added halogens	EN14582, Oxygen bomb combustion < 50 ppm
Silver Chromate Test	Pass, No Halide present	IPC J-STD-004B JIS Z 3197:1999 8.1.4.2.3
Copper Mirror Test	Pass, Low Activity, No Breakthrough	IPC J-STD-004B JIS Z 3197:1999 8.4.2
Copper Corrosion Test	Pass, Low Activity, No Corrosion	IPC J-STD-004B JIS Z 3197:1999 8.4.1
Electrical Properties
Water Extract Resistivity	11,500 ohm-cm	JIS Z 3197:1999 8.1.1
SIR (7 days, 40 °C/90% RH, 12V Bias)	Pass, ≥10⁸ Ohms, 7 days, Spacing as small as 100 µm	IPC J-STD-004B, IPC TM-650 2.6.3.7 (Pass: ≥ 1 x 10⁸ ohm)
SIR (7 days, 85 °C/85%RH)	Pass, ≥10⁸ Ohms, 7 days, Spacing as small as 100 µm	IPC J-STD-004A, IPC TM-650 2.6.3.3 (Pass: ≥ 1 x 10⁸ ohm)
JIS Electromigration (1000 hrs, 85 °C/85%RH, 48V)	Pass	JIS Z 3197:1999 8.5.4 (Pass: ≥ 1 x 10⁹ ohm)
Bono Test (85 °C/85% RH, 50V Bias)	Pass	Bono Test
Physical Properties
Color	Residue Colorless, Transparent
Tack Force Life	Pass Maintain >100 gf within 24 hrs (25 ± 2 °C, 50 ± 10% RH)	JIS Z 3284:1994, Annex 9
Tack Force Life	Pass Change <10% when stored at 25 ± 2 °C, 50 ± 10% RH	IPC J-STD-005, IPC TM-650 2.4.44
Viscosity Stability (25 °C, 14 days)	Pass	Malcom Spiral Viscometer
Coalescence - Ultra Fine Features	160 µm (SAC305, Type 5)	Internal Test Method
Solder Ball	Excellent	IPC J-STD-005, IPC TM-650 2.4.43
Spread	>80%	JIS Z 3197:1999
Wetting Time	Pass, 1.6 sec	Rhesca Test, Test Time T0
Stencil Life	~80 hours	@ 50% RH/25 °C (77 °F)
Cold Slump (25 °C / 50% RH)	Pass, No Bridge at 0.20 mm gap or above	IPC J-STD-005A
Cold Slump (25 °C / 50% RH)	Pass, No Bridge at 0.20 mm gap or above	JIS Z 3284:1994 Annex 7
Hot Slump (150 °C / 10 min)	Pass, No Bridge at 0.25 mm gap or above	IPC J-STD-005A
Hot Slump (150 °C / 10 min)	Pass, No Bridge at 0.40 mm gap or above	JIS Z 3284:1994 Annex 8
Dryness Test (Talc)	Pass	JIS Z 3197:1999 8.5.1

Halogen Status

Standard	Requirement	Method	Status
JEITA ET-7304 Definition of Halogen-Free Materials	Br, Cl, F content below 1000 ppm in soldering materials (solid)	TM EN 14582	Pass
IEC 612249-2-21	Br or Cl below 900 ppm or total below 1500 ppm in residue		Pass
JEDEC Low Halogen Electronics Definition	Br or Cl below 1000 ppm in residue		Pass
Zero Halogen: - No Halogenated compounds are intentionally added to the product.

Process Guidelines

Storage - Handling	Printing	Reflow (See Figure 1)	Cleaning
1. Refrigerate at 0 – 10 °C (32 – 50 °F) to ensure stability. Shelf life is 6 months under these conditions. Refrigeration is recommended for best performance. 2. Solder paste can be stored for up to 2 weeks at temperatures not exceeding 25 °C (77 °F) before use. 3. After refrigeration, allow container to thaw to room temperature for up to 4 hours. Paste temperature should be > 19 °C (66 °F) before use. Verify with a thermometer. Printing can be done at up to 35 °C (95 °F) and 35 – 65% RH. 4. Manually stir before use. Rotary/centrifugal stirring is not required. If used, 300 RPM for 30 – 60 seconds is sufficient. 5. Do not mix used paste from the stencil with fresh paste in the container. This will change the rheological properties.	Stencil: Recommended ALPHA CUT, NICKEL-CUT, TETRABOND™ or FORM stencils. Thickness 0.100 – 0.150 mm (4 – 6 mil). Pitch 0.4 – 0.5 mm (0.016” or 0.020”). Stencil design is influenced by process variables. Squeegee: Metal (recommended) Pressure: 0.21 – 0.36 kg/cm (1.25 – 2.0 lb/inch) in blade direction. Speed: 25 – 150 mm/s (1 – 6 inch/s) Paste Roll Diameter: 1.5 – 2.0 cm. Add paste when diameter reaches 1 cm (0.4”). Max size varies by blade type. Stencil Release Speed: 5 – 20 mm/s (0.20 – 0.79 inch/s). Lift Height: 8 – 14 mm (0.31 – 0.55”)	Environment: Recommended clean dry air or nitrogen. Profile: Soak: 155 to 175 °C for 60 to 100 seconds yields best results. See Figure 1. High soak profiles (170-180 °C for 60-120s) also yield good results, especially in nitrogen. Typical peak temp 235 to 245 °C. Note 2: Maintaining peak temperature below 241 °C reduces BGA and QFN voiding. Note 3: Refer to supplier data for thermodynamic properties at elevated temperatures. If peak temp is reduced, TAL should be extended for optimal results.	ALPHA OM-353 residues can remain on board after reflow. If cleaning is required, Vigon A201 (inline), A 250 (batch) or US (ultrasonic) is recommended. Vigon is a registered trademark of Zestron. For misprints or stencil cleaning, use ALPHA SM-110E or ALPHA SM-440.

Recommended Reflow Profiles

Figure 1: ALPHA OM-353 SAC305/SACX Plus 0307
Typical Reflow Profile (High Soak)

Figure 2: ALPHA OM-353 SAC305/SACX Plus 0307
Typical Reflow Profile (Low Soak - Preferred)

Note 4: Laboratory test results show that the reflow and coalescence performance of these profiles are satisfactory. Users will still need to optimize each individual PCB application for best results. (Note: These diagrams are not strictly drawn to scale and are for illustrative purposes only.)