Introduction

In the world of electronics manufacturing, Surface Mount Technology (SMT) has become the mainstream. However, many people believe that SMT soldering must be done in a professional factory, which is not the case. With the advancement of technology and the rise of DIY electronics, more and more small-scale reflow oven machine has found its way into personal workshops, maker spaces, and even home laboratories.

Today, we’ll discuss how to master small reflow oven from scratch, enabling you to achieve high-quality SMT soldering at home. Whether you’re an electronics enthusiast, a student, or a developer working on a startup project, this guide will open the door to professional-level SMT soldering.

I. What is reflow soldering oven? Why is it suitable for home use?

1. Introduction to Reflow Soldering oven

Reflow soldering oven involves using solder paste (a mixture of solder and flux) to connect one or more electronic components to contact pads, then melting the solder through controlled heating to achieve a permanent bond. This process can be performed using various heating methods, such as reflow ovens, infrared heat lamps, or hot air guns.

2. Advantages of Small-Scale benchtop reflow oven

In recent years, many small-scale reflow soldering ovens designed for home or small-scale use have appeared on the market, such as:

• T-962 series
• NeoDen IN6 Reflow Oven
• Open-source project Toaster Oven

These devices are typically compact, easy to operate, and affordably priced, making them ideal for beginners and hobbyists.

II. 3 Steps to Master the Entire SMT Soldering Process

We divide the entire SMT soldering process into 3 key steps: preparation phase, soldering process, and post-processing and inspection. By following the steps below, even beginners can successfully complete soldering tasks.

1. Preparation Phase — From Components to Solder Paste

a. Prepare the PCB and components

Ensure you have obtained the designed PCB board and prepared the required SMD components. It is recommended to start with larger-sized components, such as 0805 resistors/capacitors or QFP-packaged chips, to avoid the added difficulty of smaller components (e.g., 0402 or smaller).

b. Apply solder paste using a SMT stencil screen printer or stencil

Solder paste is the key material for SMT soldering. You can choose:

Manual printing: Use a squeegee and stainless steel stencil to precisely apply solder paste to the pads.

Automatic dispensing: Some high-end SMT stencil screen printers support automatic dispensing functionality, but they are more expensive.

For home users, manual printing is the most economical and practical method. Pay attention to controlling pressure and angle to ensure the solder paste is evenly distributed across each pad.  

Tip: Solder paste should be stored in the refrigerator. Thaw and mix thoroughly before use. 

c. Placing components

Use tweezers or an affordable pick and place machine (optional) to accurately place SMD components on the solder paste. It is recommended to use a magnifying glass or microscope for positioning, especially for fine-pitch components.

2. Starting the SMD reflow oven

a. Understanding the reflow soldering temperature curve

The success of reflow soldering largely depends on whether the correct temperature curve is followed. It is generally divided into four stages:

Different types of solder paste (lead-based/lead-free) correspond to different temperature curves. Please adjust the settings according to the solder paste manual.

b. Setting parameters for a small reflow oven

If you are using a reflow oven with temperature control functionality (such as the NeoDen IN6), you can set the temperature and time for each stage via the menu. For a DIY oven setup, you can use an Arduino + K-type thermocouple + solid-state relay for precise control.

c. Initiate the reflow soldering process

Once everything is ready, start the equipment and monitor the temperature changes. Ideally, the entire process should be completed within 5–8 minutes. After completion, allow the PCB to cool naturally before removing it to avoid affecting solder joint quality.

Features of NeoDen IN6 Reflow Oven

• Full convection, excellent soldering performance.
• 6 zones design, light and compact.
• Smart control with high sensitivity temperature sensor, the temperature can be stabilized within + 0.2℃.
• Original high-performance aluminum alloy heating plate instead of heating pipe, both energy-saving and high-efficient, and transverse temperature difference is less than 2℃.
• Original built-in soldering smoke filtering system, elegant appearance and eco-friendly.
  Heat insulation protection design, the casing temperature can be controlled within 40℃.
• Household power supply, convenient and practical.
• ESD tray, easy to collect PCB after reflowing, convenient for R&D and prototype.
• Several working files can be stored, freely switch between Celsius and Fahrenheit, flexible and easy to understand.
• Japan NSK hot-air motor bearings and Swiss heating wire, durable and stable.
• Reinforced heavy-duty carton package, light-weight and environment-friendly.
• PCB soldering temperature curve can be displayed based on real-time measurement
• Approved by TUV CE, authoritative and reliable.

3. Inspection and repair

a. Visual inspection

Use a magnifying glass or industrial camera system to check for obvious issues such as cold solder joints, short circuits, or misalignment. Pay particular attention to densely populated pin areas, such as IC chip pins.

b. Use a multimeter or flying probe tester to check continuity

For critical circuit nodes, it is recommended to use a multimeter to measure continuity or use a simple flying probe tester for automated testing.

c. Perform localized rework if necessary

If individual solder joints are found to be defective, use a hot air gun or soldering iron for localized rework. Ensure proper temperature and time control to avoid damaging components.

III. Common Problems and Solutions

IV. Recommended Tools and Consumables List (Suitable for Beginners)

Conclusion

SMT soldering is no longer exclusive to professional factories. With modern compact reflow oven and abundant open-source resources, anyone can achieve high-quality SMT soldering at home. As long as you are willing to get your hands dirty and learn, you can go further on the path of electronics fabrication.

If you are seeking a professional PCB production line supplier, we welcome you to contact our engineering team, and we will provide you with a one-stop SMT assembly line solution.