Open any modern electronic device—smartphone, server blade, or smartwatch—and one trend dominates: relentless miniaturization. As products shrink, the room for traditional wire harnesses disappears. The elegant answer is the board-to-board (BTB) connector, the invisible backbone that lets engineers stack or link PCBs directly, squeezing complex systems into ever-tighter spaces.
What Is a Board-to-Board Connector?
A BTB connector is an electromechanical interface that creates a separable, cable-free link between two PCBs. A typical system pairs a plug (male) with a receptacle (female); both are solder-reflowed onto their respective boards. Once mated, they deliver a secure electrical and mechanical connection that can be undone for service or upgrades.
Core Application Areas
BTB connectors shine wherever space, weight, and density are at a premium:
| Application | Benefit |
|---|---|
| Mobile & Wearables | Ultra-low-profile mezzanine connectors enable sub-millimeter stack-ups in phones, tablets, and smartwatches. |
| Servers & Networking | High-speed BTB links daughter cards to backplanes, pushing data rates beyond 25 Gbps. |
| Industrial & Embedded | CPU System-on-Modules (SoMs) snap onto custom I/O baseboards for modular, scalable designs. |
| IoT & Sensors | Sensor PCBs stack directly onto radio or MCU boards, eliminating cables in space-constrained nodes. |
| Automotive | Camera modules, ECUs, and infotainment units use BTB connectors to shave grams and cubic millimeters. |
Key Selection Factors: An Engineer’s Checklist
| Factor | What to Evaluate |
|---|---|
| Orientation | Parallel (mezzanine), perpendicular, or coplanar (edge-to-edge)? Choose the geometry that matches your mechanical envelope. |
| Stacking Height | The precise Z-distance between boards once mated—ranging from <1 mm to >20 mm. Confirm it fits inside your enclosure with tolerances. |
| Pitch | Center-to-center contact spacing. Modern designs use 0.8 mm, 0.5 mm, 0.4 mm, even 0.35 mm to maximize pin count per square millimeter. |
| Data Rate & Signal Integrity | For high-speed lanes, verify: - Impedance matching (e.g., 50 Ω, 90 Ω differential) - Shielding or ground planes to cut EMI - Insertion loss and return loss specs at target frequencies |
| Current Rating | Ensure each contact can carry the maximum continuous current without overheating (derate for temperature rise). |
| Alignment & Mating | Fine-pitch connectors need: - Self-aligning lead-ins - Tactile clicks or locking latches - Coplanarity ≤0.10 mm for reliable SMT reflow |
Design & Integration Best Practices
- Follow the Footprint
Use the exact land pattern from the datasheet; any deviation invites solder bridges or opens. - Keep-Out Zones
Respect pick-and-place nozzle clearances and extractor tool access. - Stiffeners
Add local PCB stiffeners near the connector on large or flex boards to reduce solder-joint stress during mating cycles. - Test Points
Reserve accessible test pads for boundary-scan or flying-probe tests, especially on high-density boards.
Frequently Asked Questions
Q1. Pin header vs. modern BTB—what’s the difference?
A: A pin header is the simplest BTB form, offering low density and no controlled impedance. Modern BTB connectors add fine pitch, integrated shielding, locking features, and impedance-controlled contacts in footprints smaller than a grain of rice.Q2. What is “contact wipe” and why should I care?
A: Contact wipe is the microscopic sliding motion that occurs during mating. It scrapes away oxides and contaminants, ensuring a gas-tight, low-resistance interface critical for signal integrity and long-term reliability.Q3. How do I hit tight tolerances on 0.4 mm-pitch boards?
A: Success demands a three-way partnership:
- Connector with tight coplanarity and lead-in features.
- PCB fabrication within ±0.05 mm positional accuracy.
- Placement equipment with vision alignment and ±30 µm repeatability.
JVT: Your Partner for High-Density Interconnects
As products shrink and speeds rise, JVT delivers the board-to-board connectors that make next-generation designs possible.
- Comprehensive Portfolio – Pitches from 2.54 mm down to 0.4 mm, stacking heights from 0.6 mm to 20 mm, pin counts from 4 to 400+.
- High-Speed Optimization – Differential pairs rated up to 32 Gbps NRZ, impedance-matched and EMI-shielded.
- Built for Automation – Tape-and-reel, pick-and-place friendly, and compatible with standard SMT reflow.
- Cost-Effective Innovation – Fine-pitch performance without the premium price tag.
Let’s miniaturize together.
📧 leo@jvtcn.com
🌐 www.jvtcn.cn