MacDermid Alpha ALPHA OM-340 Lead-Free Solder Paste for Fine-Pitch SMT PCB Assembly

ALPHA OM-340 Lead-Free Solder Paste for Fine-Pitch SMT

Modern electronic assemblies require precise solder deposits across increasingly small apertures and densely populated boards. ALPHA OM-340 Lead-Free Solder Paste is formulated to achieve full alloy coalescence on circular features as small as 200 μm when used with a 100 μm stencil under validated conditions. Its stable rheology supports repeatable printing across different board designs, making it suitable for consumer electronics, automotive modules, industrial controllers, communication equipment, appliances, lighting products, power supplies, and other high-density PCB applications.

The paste supports printing speeds from approximately 25 to 150 mm per second, enabling manufacturers to combine fine-feature control with fast cycle times. A wide reflow process window promotes dependable wetting on common board and component finishes, including CuOSP, ENIG, and lead-free HASL. The formulation is compatible with both clean, dry air and nitrogen reflow, giving production teams flexibility when configuring or upgrading SMT lines.

8 Benefits of ALPHA OM-340 Lead-Free Solder Paste

• Excellent print consistency: Helps reduce insufficient deposits, bridging, and variation between printed boards.
• Low head-in-pillow defects: Supports improved connection quality on advanced electronic component packages.
• Class 3 voiding capability: Meets the highest IPC-7095 voiding performance classification.
• ROL0 flux classification: Supports electrical reliability and low corrosive activity.
• Zero-halogen chemistry: Contains no intentionally added halogenated compounds.
• Clean residue appearance: Produces clear, colorless post-reflow flux residue.
• Strong pin-test performance: Helps reduce false ICT readings and unnecessary rework.
• Extended stencil life: Provides eight-hour stencil life under specified standard conditions.

Alloy, Powder, and Packaging Options

ALPHA OM-340 Lead-Free Solder Paste is available with several alloys, including SAC305, SAC405, Sn96Ag4, SACX Plus 0307, SACX Plus 0807, and Innolot. Powder options include Type 3, Type 4, Type 4.5, Type 5, and Type 6, allowing buyers to match particle size to stencil thickness, aperture design, pitch, and required transfer efficiency.

Common packaging includes 500-gram jars, 6-inch and 12-inch cartridges, and 10 cc or 30 cc dispensing syringes. Because alloy, powder size, metal loading, and package format affect processing, buyers should provide the complete required product code when requesting a quotation. Production trials should use the actual PCB, stencil, components, reflow oven, surface finish, and assembly atmosphere.

Storage and SMT Processing Guidance

Store unopened material at 0°C to 10°C to maintain stability. The published refrigerated shelf life is six months, while unopened paste may be held at temperatures up to 25°C for up to two weeks before use. Allow refrigerated containers to warm while sealed for at least four hours and confirm that the paste temperature is above 19°C before opening or printing. Keeping the container closed during warm-up helps prevent condensation.

Do not mix worked paste removed from the stencil with unused material in the original jar because this may alter rheology and printing consistency. Validate squeegee pressure, printing speed, stencil-release speed, stencil thickness, paste-roll size, reflow profile, and cleaning process for each assembly.

Official Resources and Related SMT Products

Review the official ALPHA OM-340 technical data sheet for verified processing recommendations, alloy options, classifications, storage conditions, and safety guidance. Buyers can also explore the official MacDermid Alpha solder paste portfolio for additional SMT materials.

Compare our lead-free solder pastes for fine-pitch printing, low-void assembly, and high-reliability reflow applications. You can also browse our PCB assembly consumables for compatible solder wire, fluxes, cleaners, stencils, and production accessories. Contact our sales team for pricing, current stock, cold-chain shipping, technical documents, and product selection assistance.