High-density board-to-board connectors mount between two parallel PCBs, carrying signals and power across the stack without wire runs. Fine pitch — 0.4mm, 0.5mm, 0.8mm, or 1.27mm — packs several hundred contacts into a footprint small enough to live inside a compute module.

You find them wherever a daughter board mates to a carrier: Raspberry Pi Compute Modules, NVIDIA Jetson carrier boards, SOM and SBC designs, camera modules, RF daughtercards, medical handhelds, and industrial instruments where board space is scarce.

Hirose DF40 runs at 0.4mm pitch — one of the finest in common production use — and appears in a large share of embedded module designs for that reason. Samtec SEARAY and QMS target high-speed differential work, with impedance-controlled contacts and configurable stacking heights. Molex Milli-Grid, Amphenol FCI Minitek, and TE Connectivity ERNI cover mid-pitch designs where contact count and current rating take priority over raw signal speed.

One distinction worth getting right: floating connectors have built-in X/Y tolerance — typically ±0.3–0.5mm — to absorb PCB misregistration during automated assembly. Rigid connectors have none. On a pick-and-place line, that gap is the difference between a clean first-pass yield and chronic rework.

When specifying, confirm pitch, stacking height (the mated board-to-board distance — distinct from connector height alone), contact count, current per contact, and keying against mis-mating. One thing that catches people at fine pitch: board warpage of 0.1mm or less can open contacts on a 0.4mm SMT part. Check coplanarity and your PCB stackup before finalising the layout.

TRX sources high-density board-to-board connectors from Samtec, Hirose, Molex, Amphenol, and TE Connectivity through authorised distribution. No minimum order — pull a few to qualify before committing to production volumes. In-stock lines ship to Johannesburg, Cape Town, Durban, and Pretoria. For sourced parts, we'll quote a real lead time.

Send us your part number or describe the application — we'll come back with availability and pricing.