Basics

What is it?

Reflow soldering is the process used to attach surface mount components to a PCB board. It’s convenient for boards with small components, many components, and for consistent solder joints. Unlike traditional soldering, reflow soldering relies on heating the entire board to match a temperature profile unique to the solder paste. Temperature profiles are designed to melt solder paste across the board, hold it at high temperature to form joints, then cool it quickly to solidify welds.

How it Works:

1. Solder paste is applied to pads on a PCB board with a stencil template for accurate placement.
2. Components are placed in paste, which holds them in place.
3. PCB board goes through a full temperature profile in the oven:
   1. Oven is heated to melting temperature of solder paste— solder melts.
   2. Oven is held at solder paste melting point— solder flows.
   3. Oven is quickly cooled to room temperature— solder solidifies
4. PCB board is finished!

Safety

Temperature Hazards

• The oven gets hot!!!! (Duh! It gets really hot though— like over 200 Celsius!)
• There is no safety shut off when the door is opened, so heating elements stay active until the cycle is finished or the oven is turned off. To turn off the oven use the switch on the back and never reach into the oven while it’s heating.
• The exterior body of the oven can heat up during a print— check that there is nothing flammable on top of or touching the oven.
• Even with a cool down cycle, components in the oven can remain hot after a bake is finished. Be careful handling, and note that there are heat resistant gloves available on the tool shelf.

Ventilation Hazards

• Heating solder releases fumes during the reflow process, and the oven ventilates out of the back— ensure the back vent is not covered before starting.
• The air intake vent is on the right side of the oven, make sure this isn’t blocked either!
• The oven is not currently attached to any ventilation system, so it’s just pumped out into the Sherm… If your eyes start watering, you find it hard to breathe, etc. step away from the oven and get some air!

Step-by-Step Guides

Running Pre-Made Heating Profile