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PCB Assembly

Machines for populating boards with components in the lab β€” useful for prototypes and small batches when you don't outsource to a fab. See also PCB Design.

The SMT assembly chain​

  1. Stencil printer / solder-paste jig β€” apply solder paste through a stainless stencil onto the pads.
  2. Pick-and-place (P&P) machine β€” places SMD components onto the paste from reels/trays using vision alignment.
  3. Reflow oven β€” heats the board through a temperature profile so the paste melts and solders all joints at once.

Machines & tools​

ToolRole
Stencil printerRepeatable solder-paste application
Pick-and-place machineAutomated component placement (speed + accuracy)
Reflow ovenControlled reflow soldering profile
Reflow hot plateSmall/single-sided boards, quick reflow
Hot-air rework stationPlace/remove individual SMD parts
Wave/selective solderingThrough-hole at volume (advanced)
Hand vs. machine

For one or two prototypes, a stencil + hot plate/hot air is often enough. Reach for pick-and-place + reflow when placing many parts or building several boards. See PCBA tips in From Design to Delivery.

Profiles & paste

Follow the solder paste's reflow profile (preheat β†’ soak β†’ reflow β†’ cool) and store paste correctly. A bad profile causes cold joints, tombstoning or damaged parts.