Rectangular Connectors - Board Spacers, Stackers (Board to Board)

Image	Part Number	Description / PDF	Quantity	Rfq
	M50-041103T1045 Harwin	CONN HDR 20POS 0.05 STACK SMD	0
	M20-9603746 Harwin	CONN HDR 74POS 0.1 STACK T/H TIN	0
	M22-2675005 Harwin	CONN HDR 50POS 0.079 STACK T/H	0
	M20-9602646 Harwin	CONN HDR 52POS 0.1 STACK T/H TIN	0
	M20-9611246 Harwin	CONN HDR 12POS 0.1 STACK T/H TIN	0
	M20-9603445 Harwin	CONN HDR 68POS 0.1 STACK T/H	0

Rectangular Connectors - Board Spacers, Stackers (Board to Board)

1. Overview

Rectangular board spacers and stackers are interconnect solutions designed to establish mechanical and electrical connections between two or more printed circuit boards (PCBs). These connectors maintain precise spacing while enabling signal/power transmission. Their importance in modern electronics includes enabling compact designs, modular system architectures, and reliable high-speed data transfer in applications ranging from consumer devices to industrial equipment.

2. Main Types and Functional Classification

Type	Functional Characteristics	Application Examples
Board Spacers	Fixed pitch, non-mating interconnects with insulating pillars	Smartphone mid-frames, IoT sensor modules
Stacking Connectors	Self-mating design with compressible contacts	Embedded computing boards, FPGA development kits
High-Speed Stackers	Controlled impedance, low crosstalk design	5G base stations, network switches
Compliant Pin Stackers	Press-fit terminations for Z-axis compliance	Automotive radar systems, medical imaging devices

3. Structure and Components

Typical construction includes:

Insulating housing (LCP/PBT with UL94 V-0 rating)
Phosphor bronze or beryllium copper contacts
Gold-plated contact areas (0.5-3 m thickness)
Polarization keying to prevent misalignment
Integrated locking mechanisms (latches/snap-fits)
Optional EMI shielding layers

4. Key Technical Specifications

Parameter	Typical Range	Importance
Current Rating	0.5A - 5A per contact	Dictates power delivery capability
Contact Resistance	5-20m	Impacts signal integrity
Dielectric Strength	500V - 2500V AC	Ensures electrical safety
Operating Temperature	-55 C to +125 C	Determines environmental robustness
Insertion Force	0.5N - 5N per contact	Affects assembly process
Mating Cycles	500 - 10,000 cycles	Defines service life expectancy

5. Application Fields

Telecommunications: Server backplanes, 5G NR radios
Industrial Automation: PLC modules, CNC controller stacks
Consumer Electronics: Foldable device hinge connectors
Medical Devices: MRI system detector arrays
Automotive: ADAS sensor stacking modules

6. Leading Manufacturers and Products

Manufacturer	Representative Product	Key Features
TE Connectivity	SMART Board Stacker	12 Gbps capability, self-aligning
Molex	Impel High-Speed Connector	25+ Gbps, floating compliance
Amphenol	CBGA Interposer	Micro BGA footprint compatibility
JAE Electronics	DF59 Series	0.4mm pitch, 0.3mm stack height

7. Selection Recommendations

Key considerations:

Electrical requirements vs. contact density needs
Stack height tolerance stack-up analysis
Thermal expansion coefficient matching
Field serviceability requirements
Automated optical inspection (AOI) compatibility

Case Study: In automotive camera module design, compliant pin stackers reduced assembly time by 40% while maintaining ISO 16750 vibration compliance.

8. Industry Trends

Migration to 0.3mm pitch connectors for mobile applications
Integration of coaxial contacts for RF board-to-board links
Adoption of additive manufacturing for complex shapes
Increased adoption of press-fit terminations in harsh environments
Development of hybrid optical-electrical stacking solutions