Alpha Solder Paste Selection Guide
Find the optimal solder paste for your SMT assembly process
Lead-Free & Leaded • No-Clean & Water-Soluble • Type 3/4/5 Powders • Authorized Alpha DistributorSelect alloy type
Pick the metallurgy family that matches your assembly requirements.
Lead-free vs. leaded vs. low-temp
Lead-Free is required for most consumer electronics (RoHS / WEEE). SAC305, SACX Plus, Innolot.
Leaded is still used in aerospace, military, and medical with exemptions. Lower cost, wider process window.
Low Temperature alloys reduce thermal stress on temperature-sensitive components. BiSn-based, peak reflow 155–190°C.
Select flux chemistry
No-Clean leaves benign residue. Water-Soluble requires post-reflow washing.
Which flux do I need?
No-Clean is the industry default. Residue is non-corrosive and electrically inert.
Water-Soluble gives higher spread/wetting and is preferred where any residue is unacceptable (high-voltage, medical, optics). Requires a DI-water wash.
Select your primary application
Pick what best matches your production line.
Application notes
- General purpose — broad-range PCBA, mixed components.
- Fine pitch — 0201, 0402, fine-pitch QFP, aperture under 0.5mm.
- High reliability — automotive, >125°C operating, harsh environment.
- Lowest voiding — BTC, power devices, thermal-critical.
- Jet printing — Mydata, Parmi, dispensing-only lines.
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Make your selections to see the recommended paste.
Paste Specifications
Alternative Pastes for This Application
Need a specific alloy or packaging? Our team can quote any Alpha paste variant.
Request a Quote →Alpha Solder Paste Product Reference
Full lineup organised by flux chemistry. Click any product family to see its variants on the storefront.
Lead-Free No-Clean
| Product | Alloys | Powder | Key Features | Application |
|---|---|---|---|---|
| ALPHA OM-353 | SAC305, SACX Plus | Type 4, 5 | Low HiP/NWO, fine feature, zero-halogen | Leading LF paste, ultra-fine printing |
| ALPHA OM-362 | SAC305, Innolot | Type 4 | Ultra-low voiding, IPC Class III, BTC optimised | High reliability, automotive, >125°C |
| ALPHA OM-340 | SAC305, SACX Plus, Innolot | Type 3, 4, 5 | Low HiP, excellent pin test, IPC Class III | Broad range, ICT testing critical |
| ALPHA OM-338 | SAC305, SACX Plus | Type 3 | Fine feature, ROL0, IPC Class III voiding | General purpose, proven performer |
| ALPHA CVP-390 | SAC305, SACX Plus | Type 3, 4 | Zero-halogen, JIS Cu pass, excellent pin test | Best SIR, electrochemical reliability |
| ALPHA CVP-390V | SAC305, Innolot | Type 4, 5 | Best-in-class ECR, >2.0 Cpk at AR 0.60 | Automotive harsh environment, fine powder |
| ALPHA OM-535 | SAC305, SACX Plus | Type 4 | Lowest voiding, outperforms Indium 8.9HF1 | Ultra-low void priority, power devices |
| ALPHA JP-500 | SAC305 | Type 5 | Jetting optimised, Mydata/Parmi approved | Jet printing only, 30cc syringes |
Lead-Free Water-Soluble
| Product | Alloys | Powder | Key Features | Application |
|---|---|---|---|---|
| ALPHA WS-820 | SAC305 | Type 3, 4 | Halide-free, excellent cleanability, ramp/soak profiles | Cleanable assemblies, high spread/wetting |
Low Temperature
| Product | Alloy | Melt Point | Key Features | Application |
|---|---|---|---|---|
| ALPHA CVP-520 | Sn42Bi57.6Ag0.4 | 138°C | Eliminates wave/selective, zero-halogen | Temp-sensitive PTH, multiple reflow |
| ALPHA OM-535 (SBX02) | SBX02 | ~140°C | Improved drop shock vs BiSnAg, Type 4 | Low temp SMT, consumer electronics |
| ALPHA OM-565 HRL3 | HRL3 | 175°C peak | Superior drop shock, reduced warpage | Next-gen low temp, chip-scale packages |
| ALPHA OM-550 HRL1 | HRL1 | ~175°C peak | Improved thermal cycling vs legacy BiSn | Temperature-sensitive CSP assemblies |
Leaded
| Product | Alloys | Powder | Flux Type | Application |
|---|---|---|---|---|
| ALPHA OM-5100 | Sn62Pb36Ag2, Sn63Pb37 | Type 3, 4 | No-Clean (ROL0) | Fine pitch, wide reflow window, LF-component compatible |
| ALPHA OM-5300 | Sn63Pb37 | Type 3, 4 | No-Clean | General purpose leaded |
| ALPHA WS-809 | Sn63Pb37 | Type 3 | Water-Soluble | Cleanable leaded assemblies |
| ALPHA CL-78 | Sn63Pb37 | Type 3 | Water-Soluble | High reliability cleanable |
Solder Alloy Reference Guide
Understanding the metallurgy helps you choose the right paste. Each alloy family has trade-offs in cost, reliability, and process window.
Lead-Free Alloys
SAC305
96.5Sn / 3.0Ag / 0.5Cu. 217–221°C melting. Industry standard, best hole-fill and thermal cycling reliability. Higher cost due to silver content.
SACX Plus 0307
99Sn / 0.3Ag / 0.7Cu + additives. 217–228°C melting. Low-silver alternative with ~37% cost savings vs SAC305. Patented anti-drossing.
SACX Plus 0807
98.5Sn / 0.8Ag / 0.7Cu + additives. 217–225°C melting. Medium-silver, ~27% savings. Closest performance to SAC305.
Innolot
SnAgCuNiSb. 206–218°C melting. High-reliability automotive / aerospace. Superior thermal cycling above 125°C operating temperatures.
SnCX Plus 07
Sn99.3Cu0.7 + additives. 227°C melting. Silver-free, ~41% cost savings. Drop-in for SN100C. No license fee.
Low-Temperature Alloys
Sn42Bi57.6Ag0.4
Melting ~138°C, peak reflow 155–190°C. Standard low-temp BiSn. Eliminates wave/selective for temp-sensitive PTH.
SBX02
Melting ~140°C, peak reflow 155–190°C. Improved drop shock and mechanical strength vs standard BiSnAg.
HRL1
Peak reflow ~175°C. Improved thermal cycling and drop shock. Reduced warpage vs SAC reflow.
HRL3
Peak reflow 175°C. Next-gen low-temp. Superior thermomechanical performance. Contact-rework compatible.
Leaded Alloys
Sn63Pb37
Eutectic, melts at 183°C. Standard tin-lead. Lowest cost. Wide process window. Aerospace / military exemptions.
Sn62Pb36Ag2
Melts at 179°C. Silver-bearing leaded. Better wetting on silver finishes. Improved joint strength.
Powder Size Reference
Type 3 (25–45 µm)
Standard SMT. Apertures ≥ 0.5mm. Most common.
Type 4 (20–38 µm)
Fine pitch. Apertures 0.3–0.5mm. 0402 / 0201 capable.
Type 5 (15–25 µm)
Ultra-fine. Apertures under 0.3mm. 01005 / 008004 capable.