Mechanic XG-Z40 Leaded Solder Paste Syringe - Sn63/Pb37, 183°C, 35g

Specifications

• Brand/Model: Mechanic XG-Z40

• Alloy Composition: Sn63 / Pb37 (63% Tin, 37% Lead)

• Melting Point: 183°C (361°F)

• Alloy Type: Eutectic (No plastic phase)

• Particle Size (Microns): Type 3 (20-38 µm)

• Net Weight: 35 Grams

• Packaging Form Factor: Syringe Tube

• Flux Type: No-Clean / Rosin Mildly Activated (RMA)

Key Applications and Projects

• Surface Mount (SMD) PCB Assembly: Applying dots of paste to bare circuit boards to solder micro-controllers, resistors, and LEDs using a hot-plate or reflow oven.

• BGA Reballing: Spreading the paste over a metal stencil to rebuild the microscopic solder spheres on the bottom of CPU and GPU chips in mobile phones and laptops.

• USB Port Replacement: Easily soldering the tiny, hidden pins of modern USB-C charging ports without bridging the adjacent contacts.

Unlock New Capabilities (Project Evolution) The DIY Hot-Plate Reflow Oven: Hand-soldering 50 tiny LEDs onto a custom macro-pad PCB can take hours. Evolve your assembly process! Apply a tiny dab of this XG-Z40 paste to every pad on your blank board. Drop your components onto the paste dots with tweezers. Then, carefully place the entire PCB onto an aluminum PTC heating plate (or even a modified clothes iron) set to roughly 200°C. Watch in amazement as the gray paste turns to shining silver liquid simultaneously across the entire board, soldering dozens of components in under 60 seconds with factory-level precision!

Package Includes:

• 1 x Mechanic XG-Z40 Solder Paste Syringe (35g)

FREQUENTLY ASKED QUESTIONS (FAQ)

1. What exactly is solder paste? Solder paste is a heavy, gray, putty-like material. It is a mixture of microscopic metal solder spheres suspended in a thick, sticky liquid flux. When heated, the flux burns off and the metal spheres melt together to form a solid electrical joint.

2. What does Sn63/Pb37 mean? This indicates the metal alloy composition: 63% Tin (Sn) and 37% Lead (Pb).

3. Is this paste lead-free? No. It contains 37% Lead. You must wash your hands thoroughly after handling it, and ensure your workspace is well-ventilated. It does not comply with RoHS standards for commercial lead-free manufacturing.

4. What is the melting point? The Sn63/Pb37 alloy melts at exactly 183°C. When using a hot air rework station, you will typically set your nozzle temperature between 250°C and 300°C to transfer enough heat to the board quickly.

5. Do I need to apply separate flux before using this? No. The paste already contains a high percentage of flux to clean the pads and ensure the solder flows properly.

6. Does the syringe come with a plunger to push the paste out? No, this listing is for the raw syringe tube only. You will need to purchase a separate plastic syringe plunger or use a pneumatic dispensing gun.

7. Does it come with dispensing needles? Typically no. You will need to supply your own blunt-tip dispensing needles (Luer lock style) to apply fine dots of paste.

8. What does "Microns: 20-38um" mean? This is the physical size of the metal spheres inside the paste. 20-38 microns is categorized as "Type 3" paste, which is the industry standard for general SMD work and ensures it will easily pass through most dispensing needles without clogging.

9. How should I store this paste? Solder paste must be refrigerated (typically between 2°C and 10°C) when not in use. This slows down the chemical reaction of the flux and prevents the paste from drying out.

10. Do I use it while it's cold? No. Before using the paste, you must take it out of the refrigerator and let it sit at room temperature for 2 to 4 hours. Using cold paste will result in poor dispensing and excessive moisture condensation.

11. What is the shelf life of this paste? If kept refrigerated and sealed, it generally has a shelf life of 6 to 12 months. If left out on a hot workbench, it may dry out and become unusable in a few weeks.

12. Why is my paste so hard to push out of the syringe? If the paste is incredibly stiff, it is either still too cold (needs to warm to room temperature), or it has expired and the flux has dried up.

13. Can I use a regular soldering iron with this paste? Yes. While it is heavily optimized for hot-air guns and reflow ovens, you can easily apply the paste to a pad and touch it with a standard, hot soldering iron tip to instantly melt it.

14. Is this good for soldering thick through-hole wires? It is not ideal. Solder paste is relatively expensive and designed for micro-components. Standard spool solder wire is much better, faster, and cheaper for soldering large wires or large through-hole components.

15. What is a "eutectic" alloy? A eutectic alloy (like 63/37) is a mixture that has a single, distinct melting point (183°C). It goes directly from solid to liquid without a "slushy" in-between phase, which vastly reduces the chance of cold, brittle solder joints if a component vibrates while cooling.

16. How do I clean up the residue after soldering? While it is technically a "no-clean" flux, leaving the sticky residue can look unprofessional and attract dust. Scrub the finished joints with a stiff brush and 99% Isopropyl Alcohol (IPA) to dissolve the remaining flux.

17. Why is the syringe not filled to the very top? Solder paste is extremely dense and heavy. The product is sold by weight (35g), not by visual volume. A 35g dose will not fill a 10cc syringe entirely to the brim.

18. Can I use this for plumbing or welding copper pipes? Absolutely not. This is highly specialized micro-electronic solder. It lacks the mechanical strength and acid flux required for plumbing applications.

19. Why did my paste bubble and explode when I applied hot air? You applied too much heat, too quickly. The flux liquid boiled violently before the metal could melt. Gradually heat the area from a distance to allow the flux to activate smoothly, then move the hot air nozzle closer to reflow the metal.

20. Is it safe to breathe the smoke when it melts? No. The smoke generated is vaporized chemical flux (rosin). It is harmful to inhale. You should always use a carbon-filtered fume extractor or work in a highly ventilated area.