LRM - Line Replaceable Module

Product LRM - Line Replaceable Module Product LRM - Line Replaceable Module


Nick Lidell
Product Manager
+1 (607) 563-5655


LRM surface mount connectors meet the high density needs of today’s integrated electronic modules. The flexibility in design allows Amphenol to meet and exceed the wide variety of user requirements. With multiple different contacts being used in the connectors, mainly digital (brush), there are thousands of combinations of inserts that are possible. These different configurations are all tailored to meet the needs of the customer. 

The utilization of Brush contacts with low mating force, ESD shields for Level II Maintenance and lateral float for ultimate cold wall heat dissipation make this board-to-board mating scheme the best solution for ruggedized chassis. 

Features & Benefits:

  • Available in SEM-E and custom form factors
  • B3 Brush contact – Provides low mating force, multiple points of contact, stable electrical performance and extended service life
  • ESD Protection (Module Connector)
  • Can be designed in 1, 2 & 3 bay configurations with many shell designs available.
  • Surface mount termination (Module Connector)
  • PCB or Compliant termination (Backplane Connector)
  • Typical standard arrangements of Digital (Brush) inserts – 80, 108, 152 & 180 pins
  • Inserts for power, RF, fiber optic and high speed contacts are also available
Performance Specifications

Electrical Performance

Electrical Parameters Performance
Current carrying capability 10°C temperature rise at 2A and 30°C rise at 3A
Contact resistance 30 milliohms max. per contact, 25 milliohms max. average
Dielectric withstanding voltage at sea level 100 VRMS, 60 Hz
Dielectric withstanding voltage at altitude 100 VRMS, 60Hz at 70,000ft.
Insulation Resistance 1000 megohm minimum at 100V d.c.
Electrostatic Discharge Protection (module only) ±25,000 minimum air and direct discharge


Mechanical Performance

Mechanical Parameters Performance
Contact retention (solder type backplane assembly) Maximum displacement of 0.010" at 1 pound load
Mating and unmating forces Maximum 40.0 pounds mating and unmating
Vibration (Sinusoidal, 20g peak max.)  No electrical discontinuity >1μS
Vibration (Random, 11.6g RMS max.) No electrical discontinuity >1μS
Shock (50g max. shock pulse) No electrical discontinuity >1μS
Solderability Minimum 95% solder coverage
Resistance to soldering heat 260°C dip for 10 seconds


Environmental Performance

Mechanical Parameters Performance
Temperature life 250 hours at 125°C maximum
Connector durability 500 cycles mating and unmating
Salt fog exposure 48 hours maximum direct exposure (5% NaCl)
Thermal shock 500 cycles at +125°C / –65°C
Humidity exposure 240 hours at 90 - 98%
Contamination exposure Sand and dust per MIL-STD-202 Method 110
Resistance to solvents Boiling Trichloroethylene fumes and solution
Materials List

Environmental Performance

Part Material / Finish Description
Brush wires

Beryllium copper; finish is gold over nickel (The exposed ends of the brush wires need not be plated).

Module contacts

Beryllium copper; finish on contact body is matte tin-lead; finish on termination end is 60/40 or 63/37 tin-lead dip

Backplane contacts (Compliant termination)

Contact barrel: brass; finish is tin-lead over nickel.
Contact tail: beryllium copper per; finish is gold over nickel.
Contact sleeve: stainless steel; finish is black oxide and conformally coated per MIL-I-46058.

Backplane contacts (PCB termination) Contact body: brass; finish is gold over nickel; termination end is 60/40 or 63/37 tin lead dip.
Contact sleeve: stainless steel; finish is black oxide and conformally coated per MIL-I-46058.
Insulators Polyphenylene Sulfide or Liquid Crystal Polymer.
Organizer Polyphenylene Sulfide or Liquid Crystal Polymer.
Shells Aluminum alloy; finish is electroless nickel.
ESD shields Aluminum alloy; finish is hardcoat anodize with epoxy final coat. Ground tabs are chromate treated (irridite).
Polarization keys Stainless steel; finish is black oxide. Key retaining ring is Polyamide (nylon 12) with 50% glass filled fibers.
Guide pins Beryllium copper alloy; finish is gold per over nickel.
Part Number Guide

Component Breakout

Brush Contact Technology


Brush Contacts vs. Conventional Pin and Socket Contacts

Brush Contact Innovation

  • Multiple contact interfaces - Strands of high tensile wire are bundled together to form brush-like contacts. By intermeshing two multi-strand wire bundles, an electrical connection is made.
  • Provides redundant current paths, 14-70 (points of contact) per mated contact with a gas-tight junction
  • Very smooth (low friction) interface

Conventional Pin and Socket

  • Machined surface finish on both parts
  • Higher friction and wear
  • Limited number of contact sites
Typical Arrangements

Contact Patterns

LRM Hybrid Options

Board Level and Rectangular Interconnects Catalog
Board Level and Rectangular products includes LRM, Ruggedized VME 64x/VITA 60, 66, High Density HDB3 & HSB3, Low Mating Force, Rack & Panel Brush, LMD/LMS and more.
LRM Catalog Section
Amphenol® LRM Surface Mount Connectors meet the high density needs of today’s integrated electronic modules
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