In the fields of industrial automation, rail transit, medical electronics, and new energy, the long-term stability of connectors has always been one of the important factors affecting system reliability. Especially for connectors used in high-temperature environments, the "aging failure" problem often directly determines the service life and safety performance of the equipment. This article takes Japan's TAJIMI Electronics (Takaoka Mamiya Electronics) as a reference case, discusses the failure mechanism of domestic connectors after high-temperature aging, and proposes improvement directions.
TAJIMI Electronics brand and technology overviewTAJIMI Electronics was established in 1923, with its headquarters located in Takayama City, Gifu Prefecture, Japan, and is one of Japan's professional circular industrial connector manufacturers. Its products are widely used in communication equipment, industrial control systems, medical instruments, vehicle and aviation equipment, and other fields.
The representative product series such as R04, EPRC05, and T.R.C series have the following technical features:
● Strong high-temperature resistance: Some series adopt high-performance engineering plastics such as PPS, PEEK, which can withstand continuous working temperatures above 120℃.
Gold-plated contact design: reduces contact resistance while effectively preventing oxidation and corrosion.
●High protection level: Some models support IP67/IP68 and other waterproof and dustproof standards.
●Long mechanical life: typical insertion and extraction life can reach more than 2000 times.
These technical characteristics provide an important benchmark for domestic brands in high-temperature aging tests and failure analysis.
Secondly, common failure mechanisms of domestic connectors after high-temperature aging.Contact oxidation and coating diffusion
Under high-temperature conditions, the plated layer (such as gold or nickel) on the connector contact surface will undergo metal atom diffusion. When the thickness of the plated layer is insufficient or the base material control is not strict, the underlying copper or nickel will migrate to the surface, causing an oxide film to form on the contact surface, thereby increasing the contact resistance and ultimately leading to signal distortion or power loss.
A multi-layer composite coating structure (such as gold/nickel/copper) and strict control of the gold coating thickness at ≥1.27μm can effectively delay the diffusion of high temperature.
Insulation material thermal aging and decrease in dielectric properties
Insulating materials commonly used in domestic connectors, such as PA66 and PBT, are prone to thermal decomposition at temperatures above 100℃, leading to a decrease in dielectric strength and volume resistance.
This may cause signal interference, arc discharge, and even insulation breakdown.
The high-end series of TAJIMI uses heat-resistant materials such as PPS, LCP, and PEEK, which can ensure structural stability under 150℃ conditions.
Improve the insulation material grade of domestic connectors, select engineering plastics with high Tg and low moisture absorption, and screen formulations through aging tests.
3. Shot Material Fatigue and Stress Relaxation
High temperatures can accelerate the creep and fatigue of metal splinters, gradually reducing the contact pressure, causing "contact instability" or "loose contact". Particularly in equipment operating at temperatures above 85℃ continuously, such problems are most typical.
Select high elastic alloys such as beryllium copper (BeCu) or phosphor bronze, and optimize the shape of the spring strips through stress analysis at the design stage to delay fatigue.
Seal ring aging and protective failure
国产connectors, if using ordinary silicone or nitrile rubber, will become hard, crack, and deform in high-temperature cycles, leading to the attenuation of waterproof performance.
TAJIMI uses high-temperature resistant fluororubber (FKM) seals, ensuring that the protective performance remains stable at 150℃.
Domestic substitute products must select the appropriate sealing materials according to the working environment and conduct high temperature and high humidity aging tests for verification.
Part three: Failure Analysis Detection MethodsIn the verification process of domestic connectors, the following testing methods are usually adopted to assess the risk of high-temperature aging:
1. Constant temperature aging test: Simulate the long-term high-temperature operation of the product and evaluate the change of contact resistance.
High temperature and high humidity cycle: observe coating corrosion and aging of sealing structures.
Test of mechanical life and insertion retention force: inspect the fatigue degree of the spring pin.
4. Insulation withstand voltage and leakage current test: Determine the trend of insulation performance changes.
These methods, when compared with TAJIMI products under the same conditions, can directly reflect the reliability gap between domestic substitute products.
Path to improve the high-temperature resistance of domestic connectors● Process optimization: introduce vacuum gold plating and automatic electroplating line, control the coating thickness and uniformity.
●Material upgrade: adopts high-temperature engineering plastic and high elasticity copper alloy;
● Improvement in sealing technology: upgrading the material and structure of gaskets to achieve a higher protection level;
● Standardization verification system: Establish a high-temperature aging test process consistent with international brands to ensure the accuracy of life prediction.
Through continuous improvement in these directions, domestic connectors are gradually narrowing the gap with international brands in terms of high-temperature performance and reliability.
The failure of connectors after high-temperature aging is essentially the result of the combined effects of material aging, structural fatigue, and chemical diffusion.
TAJIMI Electronics provides a reliable technical reference for the industry with rigorous manufacturing standards and high-temperature design philosophy. Domestic manufacturers should combine failure mechanisms to systematically optimize materials, processes, and design during the process of domestic substitution in order to truly achieve long-term stable operation under high-temperature environments.
If you are interested in the domestic substitute products of the TAJIMI brand connectors or have procurement needs, or if you have production or sales channels for these brand connector domestic substitute products and wish to engage in in-depth cooperation or communication, please contact via the following contact information:
Manager Zhang (18665383950, WeChat number the same)We look forward to working with more industry partners to jointly promote the high-reliability development of domestic connectors.
