Verification of resistance to yellowing and aging of electronic connectors

Product Description

Item Specification

1. Internal chamber size(W*D*H) 50*50*60cm

2. External chamber size(W*D*H) 114*74*130cm

3. Temperature Range Ambient Temperature~200

4. Control Mode Automatic Calculation Controller

5. Temperature display accuracy 0.1

6. Control accuracy 3

7. Distribution accurac 1 (ambient ~ 100)

8. Time memory 0-999 hours, Power Failure Memory Type, with Buzzer

9. Sample holder rotation speed Diameter 45cm, 102 roll/min

10. UV light source 300W UV lamp

11. Heating method Hot air circulation

12. Chamber material Internal: Stainless Steel SUS304;

13. External: Steel plate with baking varnish

For the verification of yellowing resistance of electronic connectors, it is necessary to focus on verifying the yellowing resistance of materials and stability of electrical performance in ultraviolet (UV), high temperature, humidity and heat, etc. It is suitable for reliability testing of connectors in the fields of automobiles, consumer electronics and industrial equipment. The following are the technical points and verification program:

1. Principle of yellowing-resistant aging test

Aging mechanism:

Light aging: ultraviolet light (wavelength 290-400 nm) triggered polymer materials (such as PA, PBT, PC) chain breakage, resulting in surface yellowing.

Heat aging: High temperature (>85C) accelerates the oxidation reaction, prompting plasticizer volatilization or material crystallization.

Moist heat aging: moisture penetration leading to material hydrolysis (e.g. PET) or interfacial corrosion (metal terminals).

Test Objective:

Verify the color stability (E 1.5) of connector housings and insulators in long-term use.

Ensure that electrical properties such as contact resistance, insulation resistance, etc. comply with standards (e.g. IEC 60512).

2. Test equipment and conditions

(1) Core equipment

UV aging tester:

Light source: UVA-340 (simulated solar spectrum) or UVB-313 (accelerated aging).

Irradiation intensity: 0.5-1.5 W/m/nm @340 nm (adjustable).

Constant Temperature and Humidity Chamber:

Temperature range: -40C ~ +150C, Humidity: 10%-98% RH.

Colorimeter:

Measurement parameters: CIE Lab E value (accuracy 0.05), quantifying the degree of yellowing.

(2) Test conditions (example)

Test Type Condition Parameter Standard Basis

UV aging 60C, UVB-313 light 8h + condensation 4h, cycle 1000h ASTM G154

High temperature aging 125C, 1000h IEC 60068-2-2

Damp heat aging 85C/85% RH, 1000h IEC 60068-2-78

3. Test procedure and evaluation method

Pretreatment:

Samples are equilibrated in a standard environment (23C, 50% RH) for 24 hours.

Initial performance test:

Color measurement: Initial Lab* values are recorded using a colorimeter.

Electrical test: contact resistance (20 m), insulation resistance (100 M).

Aging test:

Accelerated aging under preset conditions (e.g. UV + high temperature cycle).

Mid-term testing:

Take samples every 250h, observe surface cracks and deformation, and record E value.

End point evaluation:

Appearance inspection: visually compare the color cards (e.g. Pantone color number) and confirm that there is no significant yellowing.

Electrical performance: contact resistance change rate 10%, insulation resistance 10 M.

Mechanical properties: Plugging and unplugging force attenuation 15% (refer to EIA-364-13 standard).

4. Key influencing factors and material optimization

Material selection:

Anti-UV additives: add benzotriazole light stabilizers (e.g. Tinuvin 326).

Heat-resistant resin: Select LCP (liquid crystal polymer) or PPS (polyphenylene sulfide).

Process improvement:

Control mold temperature during injection molding (e.g. PBT needs 80-100C) to reduce yellowing caused by internal stress.

Optimization of metal terminal plating (e.g. gold/tin plating, thickness 0.5 m).

5. Test standards and industry norms

International Standard:

IEC 60512-11-14: Environmental test methods for connectors (including weathering test).

ISO 4892-3: Laboratory light source exposure test for plastics (Xenon/UV lamp).

Industry Specification:

Automotive electronics: USCAR-2 (high temperature durability), LV214 (hot and humid aging).

Consumer Electronics: Apple MFi certification (color stability requirements).