What is PCB assembly?
PCB assembly (PCBA) is the process of mounting and soldering electronic components onto a bare printed circuit board. Surface-mount (SMT) parts are placed onto solder paste by a pick-and-place machine and soldered in a reflow oven. Through-hole (THT) parts — connectors, headers, large capacitors — are inserted and soldered afterwards. The result is a working circuit board ready for firmware and testing.
Our assembly process
- StencilSolder paste printed on the pads
- Pick-and-placeNeoDen N9 / YY1 placement
- ReflowPaste melted into joints
- Through-holeConnectors hand soldered
- InspectionBoards checked after soldering
Machines
SMT placement runs on two NeoDen pick-and-place machines: an N9 with 53 feeder slots and a YY1 with 45. Fine-pitch and BGA parts are quoted per part.
One or both sides
We assemble boards with components on the top side only, or on both sides. Double-sided boards need a stencil per side.
For the detail of stencil, placement and reflow, see SMT assembly.
Components: we source, or you supply
There are two ways to supply parts:
- We source them. Send your BOM; we check every line, propose substitutions where a part is unavailable, and quote components after that check. Common passives, LEDs, diodes, regulators, crystals and USB-C connectors are held in stock.
- You supply a kit. Send components for the batch, labelled by MPN. Allow for setup loss on reels and cut tape.
You can check what we stock and price a BOM instantly with the BOM pricer.
What we need for a PCB assembly quotation
| Item | Why it matters |
|---|---|
| Board quantity | Setup, stencil and feeder loading are spread across the batch. |
| Sides populated | Double-sided boards need two stencils and two placement passes. |
| SMT parts per board | The main driver of placement time. |
| Fine-pitch and BGA parts | Quoted separately from standard SMT parts. |
| Through-hole pins per board | Hand-soldered after reflow. |
| Unique BOM lines | Each line is a feeder to load and a part to source. |
| Stencil | We make it, or you supply one. |
| Component supply | Sourced by us or kitted by you. |
For production, send one .zip with Gerbers (with paste layers), a BOM with designator, value, footprint, MPN and quantity, and a pick-and-place (centroid) file. An assembly drawing PDF helps. Exports from KiCad, Altium, EasyEDA and Eagle all work. The instant quote tool prices assembly from these numbers before you send anything.
After assembly
Boards are inspected after soldering. For ESP32 and ESP32-S3 designs we can flash firmware as part of the job, and functional testing can be scoped with you in the quote. Assembled boards can go on into enclosures, marking and packing.
Frequently asked questions
What is PCB assembly?
PCB assembly is mounting and soldering components onto a bare printed circuit board: SMT parts are placed on solder paste and reflowed, and through-hole parts are soldered afterwards.
Does CktHub do small-batch PCB assembly?
Yes. Boards are assembled on CktHub's own NeoDen pick-and-place line in Pune, from single prototypes to small production batches.
Can I provide my own components?
Yes. You can supply a kit of components, or CktHub can source them; sourced components are quoted after a BOM check.
How long does PCB assembly take?
Typical turnaround is 5 to 8 days, as listed on the fab quote page. It depends on component availability and batch size, and is confirmed in your quote.
Do you assemble through-hole components?
Yes. Through-hole parts such as connectors and headers are hand soldered after SMT reflow.