PCB board cold and hot impact test box

1PCB board cold and hot impact test boxScope of application

This solution is applicable to PCB bare boards, PCB components with components, and high-frequency high-speed PCB boards for 5G base station equipment, routers, intelligent terminals, and other products

2、 Test basis (refer to industry standards)

1. IEC 60068-2-14:2009 "Environmental testing - Part 2-14: Test methods - Test N: Temperature changes"

2. GB/T 2423.22-2012 "Environmental testing for electrical and electronic products - Part 2: Test methods - Test N: Temperature changes"

3. IPC-TM-650 2.6.7 "Temperature Shock Test Method"

IIIPCB board cold and hot impact test boxTest equipment parameters (thermal shock test chamber)

1. Temperature range: Low temperature zone: -65 ℃~0 ℃; High temperature zone: 60 ℃~150 ℃

2. Temperature shock rate: Switching time between high and low temperature zones ≤ 5 seconds (temperature change rate in the sample area)

3. Temperature uniformity: ± 2 ℃ (at any point within the working room)

4. Temperature deviation: ± 3 ℃ (difference between set temperature and actual temperature)

5. Cycle times: can be set to 100-1000 times (adjusted according to accelerated aging requirements)

6. Studio ruler: not less than 500mm x 500mm x 500mm (compatible with PCB component size)

7. Cooling method: air-cooled/water-cooled (to meet the requirements of continuous long-term operation)

8. Control mode: Program control, supporting temperature curve editing and cycle number setting

5、 Test sample requirements

1. Sample quantity: 3-5 pieces per group (same batch, same specification PCB board/component);

2. Sample condition: No obvious scratches or warping, size meets design requirements;

3. Components with components: Welding has been completed without virtual soldering or solder leakage, and the components are firmly soldered;

4. Sample pretreatment: Place the sample in an environment of 23 ℃± 2 ℃ and 50% RH ± 5% for 24 hours before the experiment.

4、 Box structure and materials:

1. Outer box material: double-sided galvanized steel plate, surface spray treated;

2. Inner box material: stainless steel plate SUS # 304;

3. Box insulation material: rigid polyurethane foam+glass fiber;

4. Door insulation material: rigid polyurethane foam

5. Air conditioning channels: fan, heater, evaporator, damper, temperature sensor;

6. Standard configuration: 2 sample compartment racks, 4 adjustment feet, 6 adjustment wheels, and 1 power cord (3 meters long);

5、 Refrigeration/dehumidification system and working principle:

1. Refrigeration system and compressor: In order to ensure the cooling rate and temperature requirements of the test chamber, the refrigeration system of this test chamber adopts a cascade refrigeration system composed of two French Taikang semi closed compressors. This refrigeration system has the advantages of reasonable matching, high reliability, and easy use and maintenance

2. Working principle of refrigeration: The refrigeration cycle adopts the reverse Caryol cycle, which consists of two isothermal processes and two adiabatic processes. The process is as follows: the refrigerant is adiabatically compressed to a higher pressure by the compressor, consumes work to increase the exhaust temperature, and then the refrigerant exchanges heat with the surrounding medium through the condenser isothermal, transferring heat to the surrounding medium. After the refrigerant undergoes adiabatic expansion through the shut-off valve, the temperature of the refrigerant decreases. Finally, the refrigerant absorbs heat from the object at a higher temperature through the evaporator, causing the temperature of the cooled object to decrease. This cycle repeats itself to achieve the goal of cooling down

3. The design of the refrigeration system applies energy regulation technology, which is an effective processing method that can ensure the normal operation of the refrigeration unit while effectively adjusting the energy consumption and cooling capacity of the refrigeration system, reducing the operating costs of the refrigeration system to a more economical state;

4. High quality oxygen free copper tube, nitrogen filled welding;

5. Set up a condensate water collection tray and discharge it outside the box;

6. Vibration reduction: using compressor spring vibration reduction;

7. Noise reduction: using special sound-absorbing sponge for sound absorption;

8. Refrigerant: Environmentally friendly refrigerants R404A and R23 are used;

9. Refrigeration accessories: Both refrigeration accessories and control components are made of international brands, such as SPORLAN thermal expansion valves from the United States, CASTEI solenoid valves from Italy, globe valves, and filters; RANCO pressure controller from the United States, etc.

10. Refrigeration compressor: using original French "Taikang" fully enclosed; The Taikang compressor, known for its small size, light weight, low noise, high efficiency, and long lifespan, is renowned worldwide in the refrigeration industry. In particular, the Taikang compressor's noise resistant design, high efficiency, and energy-saving black like design are widely used in refrigerated display cabinets, vending machines, vehicle and ship refrigerators, household and commercial refrigerators, refrigeration machines, dehumidifiers, low-temperature experimental equipment, and low-temperature equipment.

4、 Heating and air circulation system:

1. Adopting a multi blade centrifugal circulating fan with reinforced shaft and high and low temperature resistant rotating blades made of aluminum alloy to achieve forced convection;

2. High temperature/ambient temperature exposure fan: 3 Φ, 400W centrifugal type; Low temperature exposure fan: 3 Φ, 400W centrifugal type;

3. Nickel chromium alloy electric wire heater;

4. Heater control mode: contactless equal period pulse width modulation, SSR (solid-state relay)