The proper functioning of Molex connector wiring requires the crimping height error to be kept within ±0.02mm, and when using professional crimping tools (e.g., Molex 63811-1000), the crimping path should be consistent between 35-45N. The IPC/WHMA-A-620D standard test in 2023 states that the contact resistance of the well-crimped terminal is less than 5mΩ (initial value), and the resistance difference is less than 0.3mΩ after 500 insertions. A report of an automotive electronics producer found that the use of torque control screwdriver (0.6N·m±5%) for the assembly of Molex connectors reduced the assembly defect rate of wiring harness from 0.12% to 0.003%.
Wire stripping length must be accurate to 1.5±0.1mm (AWG22 wire gauge), and the use of laser strippings machine (accuracy ±0.05mm) can avoid copper core damage. Although the manufacturing of the medical device, a medical equipment manufacturer lowered the bit error rate of signal transmission from 10⁻⁶ to 10⁻⁹ by improving the molex connector wiring process, which meets the IEC 60601-1 electromagnetic compatibility standard. The heat shrinkage temperature of the insulation layer should be controlled to 125 ° C ±5 ° C, and the heating time should be 3-5 seconds for it to enable the shrinkage rate to be ≥50% and there should not be bubble formation.
Terminal insertion should be controlled by the “click” sound feedback mechanism, an industrial robot production line test data shows that when the insertion force is 12-15N, terminal locking success rate is 99.97% (manual operation average 98.2%). The polarity detection fixture (error ±0.05mm) can avoid reverse insertion accidents, and the short circuit fault caused by wiring errors is reduced by 92% after application by an energy storage system integrator. For the high-density connectors such as the Molex 502570 series, terminals with a pin pitch of 0.4mm need to be aligned using microscope support, and the offset tolerance is ≤0.03mm.
In solder welding, the solder temperature needs to be maintained at 260 ° C ±10 ° C, and the welding time should not be more than 3 seconds. NASA JPL lab test cases show that in case of wiring by Molex connectors with soldering by Sn96.5Ag3Cu0.5, the tensile strength of solder joint is 45MPa (28% increase in tensile strength compared to normal solder) and fatigue life is more than 5000 times for thermal cycle test at -65℃ to 150℃. The height of climbing solder should be no more than 1.5 wire diameters (AWG20 line, 1.14mm), and the rate of X-ray detection-exposed hole is below 5% (Class 3 level of IPC standard).
In test and inspection phases, MIL-STD-1344 Method 3009 insertion force removal test (50 cycles, 25mm/min insertion and withdrawal speed) shall be performed. The reduction of holding force of qualified connectors should be less than 10%. In Molex connector wiring optimization, the VSWR of RF connectors was reduced from 1.25 to 1.05 by one satellite communication equipment maker, reducing signal loss by 68%. At detection with a network analyzer (e.g., Keysight PNA), the impedance matching error should be kept within ±1Ω (DC-6GHz frequency band) for high-speed signal integrity. These very strict process conditions and test levels enable Molex connectors to attain a 99.999% yield in high-reliability applications such as aerospace and automotive electronics.