THT · Through-Hole Assembly
Through-hole, done right — wave or selective.
Power supplies, industrial controllers, and connector-dense boards still depend on through-hole. Full wave, selective wave and hand rework — IPC-A-610 Class 3 delivered by default.
- Lead-free wave
- SnCu
- Peak temp
- 265 °C
- Default class
- IPC 3
- Wave modes
- Sel + full
3 Soldering Methods
Pick the right tool for the joint
Where THT Still Rules
THT isn’t obsolete — these need it
- Switch-mode PSU · high-current transformer pins
- Industrial controllers · connector headers
- Relays · fuse holders · terminal blocks
- Large through-hole electrolytic capacitors
- DC/DC module connectors
- LED filament bulbs · high-power fixtures
- Legacy audio / HiFi circuits
- Dev boards & test jigs
THT Capability
Published THT spec
| Soldering | |
| Wave soldering | Full wave · Selective wave (Nordson Asymtek) |
|---|---|
| Solder alloys | SAC305 (Pb-free) · Sn63/Pb37 · SN100C |
| Peak temp | 245–265 °C · profile per BOM |
| Flux | No-clean (rosin-based) · water-soluble (OSP / ENIG) |
| Components | |
| Lead diameter | 0.4 – 2.0 mm |
| Component height | Up to 25 mm |
| Connector pitch | 1.0 mm – 10.16 mm (0.4" DIL) |
| Mixed technology | |
| SMT + THT on same board | Yes — SMT side passes reflow, THT bottom selective-waved |
| Inspection | |
| AOI | Applied to SMT side · THT visual per IPC-A-610 |
| X-ray | For press-fit connectors and hidden joints |
| Compliance | |
| Standards | IPC-A-610 Class 2 / 3 · IPC-J-STD-001 |
Frequently Asked Questions
THT Assembly FAQ
01Full wave or selective wave — which to pick?
If your board has SMT components on the same side as through-hole pins, go selective wave. The nozzle only touches specific holes, leaving SMT untouched. Full wave is faster but requires SMT-free bottom.
02Can you do lead-containing (SnPb) soldering?
Yes — for military, medical and long-service industrial products where RoHS exemptions apply. We maintain a separate SnPb line to avoid contamination.
03How do you prevent solder bridging on fine-pitch connectors?
We run an in-line flux optimizer, and we may use custom titanium pallets to mask adjacent pins. For < 1.5 mm pitch we often switch to hand soldering with IPC-J-STD-001 certified operators.
04Can you press-fit connectors?
Yes — we run hydraulic press-fit stations for high-density backplane connectors (compliant with IPC-9797). X-ray verified on every shipment.
Ready when you are
Send your Gerber & BOM — get a quote in 24 hours.
NDA available · Free DFM review · Senior engineer response.