S-DS300 Automatic Dip Soldering Machine: Batch THT Soldering for Long-Lead Components | Southern Machinery

Manual soldering of long-lead, through-hole components is one of the most persistent bottlenecks on a mixed SMT/THT line. Every connector, transformer, relay and large electrolytic capacitor that is hand-soldered adds labor cost, cycle time and quality variation. The S-DS300 Automatic Dip Soldering Machine from Southern Machinery replaces that manual step with a programmable batch soldering process: boards travel into the machine, flux is applied by a tracking spray system, and the soldered side of the board is dipped into an 85 kg lead-free tin furnace under PLC control.

What is this machine used for?

The S-DS300 is an automatic dip soldering machine for through-hole (THT) PCBs. Instead of a moving solder wave, a dip soldering machine lowers the board onto the surface of a solder pot, holds it for a set dwell time, and lifts it out. This makes it a practical middle route between hand soldering and a full Wave Soldering machine, especially for boards with long leads, tall components, or mixed batches where a wave solder line is not economical.

Southern Machinery positions the S-DS300 specifically for long-lead insertion welding — assemblies where component leads extend well below the PCB and would be difficult to control in a standard wave process.

Key features of the S-DS300 (documented)

The following features are taken from Southern Machinery's official S-DS300 catalog:

• 7-inch touch screen + PLC intelligent control and temperature control system
• Intelligent precision step-by-step feed with an imported wire rod system for repeatable solder supply
• Tracking step-type automatic spray system for flux application
• 85 kg small-capacity lead-free tin furnace — sized for medium-volume production rather than a full wave line
• Maintenance-free spray system and automatic solder supply
• Three-section transmission with manually adjustable width for different board sizes
• Automatic pure tin slag removal to keep the solder surface clean and joints consistent
• Tin furnace liquid level auto-detection with over-temperature protection on both the furnace and the preheat stage
• New far-infrared heating technology with a ductile cast iron heating plate — documented as approximately 40% energy saving versus conventional heating
• Strong wind cooling device at the outfeed to stabilize the solder joint before handling
• Automatic PCB entry for semi-automatic line integration

Southern Machinery documents the operating-cost advantage of this approach: roughly USD 28,000 per year saved compared with a high-energy Wave Soldering setup, and about USD 16,000 per year compared with a double-wave soldering line (manufacturer's claims from the S-DS300 catalog — verify against your own energy tariff and duty cycle).

Typical applications

Dip soldering is used where a full Wave Soldering line is oversized, or where the product mix makes a solder pot the lower-risk option:

• Power supply boards — transformers, large capacitors and heat-sensitive parts that are hard to wave solder
• LED lighting and LED display boards — long-lead LED components soldered in batches
• Home appliance control panels (air conditioner, microwave, induction cooker, electric kettle)
• Industrial control boards, security and alarm panels, power amplifier boards
• High-mix EMS / ODM lines where batch changeover is frequent and fixtures are used to group boards
• Prototype-to-production transfer — many EMS shops validate dip soldering before committing to a wave line

Southern Machinery's documented application notes for the dip soldering family cover circuit boards, LED boards, toy boards and transformer products, typically with a fixture (jig) to hold multiple boards per cycle.

How it fits into a complete PCB assembly line

The S-DS300 sits on the THT side of the line, after insertion and before inspection:

1. SMT side first — solder paste printing, Pick and Place, Reflow Oven, optional SPI/AOI
2. THT insertion — radial, axial or odd-form insertion machines (for example the S-3010A radial inserter or S-7040 odd-form inserter)
3. Dip soldering — the S-DS300 solders the inserted components in batches
4. Post-soldering processing — lead cutting, cleaning, and inspection (AOI for DIP joints)

Southern Machinery supplies the whole chain: since 2011, the Shenzhen-based company has served 237+ customers globally with SMT, THT, Wave Soldering, board handling and inspection equipment, and can engineer a full line around your specific board set. The S-DS300 is one module of that line — a cost-controlled soldering step between manual work and a full wave line.

Key selection parameters (confirm with Southern Machinery)

Because the right dip soldering configuration depends on your board set, confirm these parameters when requesting a configuration:

• Maximum PCB size the machine must accept (length, width, thickness)
• Solder pot capacity and type — lead-free alloy compatibility, pot dimensions, and how often the pot must be changed
• Solder dwell height and dwell time — the immersion depth and soak time that match your lead lengths
• Temperature control — required solder temperature range, PID stability, and preheat capability
• Flux application method — spray fluxing vs. other options, and whether flux residue must be cleaned afterward
• Batch layout / fixtures — number of boards per cycle and fixture design support
• Energy supply — power requirements, air supply, and the machine footprint for your floor plan
• Throughput per shift — boards per shift at your target cycle time, to size the machine correctly

ROI, quality and capacity

The business case for automatic dip soldering is usually built on three lines:

• Labor: one operator supervises batch soldering instead of several hand-solderers; the manual process disappears from the critical path.
• Quality: PLC-controlled dwell time and temperature remove the "good solderer vs. bad solderer" variation; automatic slag removal and liquid-level detection keep the joint quality consistent across batches.
• Energy: a small tin furnace with far-infrared heating consumes far less energy than a full wave line — the documented saving of roughly USD 16,000–28,000 per year comes precisely from not running a large soldering system for medium volumes.

For an EMS or ODM evaluating soldering routes, the S-DS300 is worth comparing against three alternatives: hand soldering (labor and variation), selective soldering (higher flexibility, higher machine cost), and a full Wave Soldering line (higher throughput, higher energy and footprint). Dip soldering wins when the product is batch-oriented, lead lengths are long, and the board mix changes often.

FAQ

Is a dip soldering machine the same as a Wave Soldering machine?

No. A Wave Soldering machine pumps a continuous wave of solder against the board, while a dip soldering machine lowers the board onto a static solder pot surface for a set dwell time. Dip soldering is simpler, smaller and lower-cost, and suits batch production of long-lead THT components.

What kinds of components is the S-DS300 used for?

Connectors, transformers, relays, large electrolytic capacitors and other through-hole parts with long leads — typical of power supply, LED, appliance and industrial control boards.

Can the S-DS300 run lead-free solder?

Yes. The documented configuration uses a small-capacity lead-free tin furnace with temperature control, liquid-level detection and over-temperature protection.

Does it replace manual soldering workers?

In typical installations it replaces most hand soldering for batch THT boards, with one operator supervising the cycle. Labor savings depend on your board volume and mix — Southern Machinery can size the payback on your actual production data.

Is the machine suitable for high-mix, low-volume EMS production?

It is a good fit for high-mix lines because board size is manually adjustable, the process is batch-based, and fixtures group multiple boards per cycle. Changeover is a fixture and recipe change rather than a line rebuild.

Where can I see it working?

Southern Machinery's official YouTube channel (SMT solution provider) shows automatic PCB DIP soldering and the automatic lead-free dip tin stove in operation.

Get a configuration recommendation

Every dip soldering line starts with four numbers: PCB size, lead length, boards per shift, and solder alloy. Send those to Southern Machinery and the engineering team will recommend the right machine size, pot capacity, fixtures and line position — plus a cost comparison against manual soldering, selective soldering and Wave Soldering for your case.

• Contact Southern Machinery for a configuration proposal and ROI estimate: Jason Wu, jasonwu@smthelp.com, +86 13602562576, or via https://www.smthelp.com
• Browse the full product catalog and PDFs at https://file.autoinsertion.com (Southern Machinery Product directory)
• See machine photos at https://ph.smthelp.com