The SMT workshop has clear requirements for temperature and humidity. Proper temperature and humidity are one of the important methods to prevent PCB defects. If the environmental conditions of the factory are not well controlled, it may damage the components, or even the entire assembly, resulting in quality Problems and unnecessary costs. The following FASTPCBA SMT factory shares the importance of temperature and humidity, workshop temperature and humidity standard parameters, and management standards.

1. Requirements for temperature and relative humidity in SMT workshop:

Temperature: 24±2℃

Humidity: 60±10%RH

2. Temperature and humidity testing equipment:

PTH-A16 precision temperature and humidity inspection instrument

* Use Pt100 platinum resistance as temperature sensor to ensure the accuracy and stability of temperature measurement;

* The relative humidity is measured by the ventilated dry-wet bulb method, which avoids the influence of wind speed on humidity measurement;

* Resolution: temperature: 0.01℃; humidity: 0.01%RH;

* Overall error (electrical measurement + sensor): temperature: ±(0.1～0.2)℃; humidity: ±1.5%RH.

3. Relevant regulations for environmental control in SMT workshop:

* The parameter values are set by the SMT Engineering Department according to product requirements and seasonal changes.

* Placement of the daily thermometer and hygrometer: the electronic pointer type dry and wet bulb thermometer and hygrometer are used, placed in the densest area of the machine, so that the most significant temperature and humidity changes can be collected.

* The recording period of the thermometer and hygrometer is set to 7 days, and the recording table is changed every Monday at 7:30 in the morning. The replaced record sheet is stored in a specific folder, and the retention period is at least 1 year. The new record sheet can be applied to the Engineering Department. The start date must be stated on the form. When the record sheet is replaced, the record start time must be the same as the replacement form.

* The switch of the indoor air-conditioning system and the humidity control system (humidifier, humidifier) switch are handed over to the relevant personnel of the Public Works Department, and personnel from other departments are not allowed to use them without authorization.

* The exhaust port of reflow soldering must be cleaned once a month to prevent excessive water accumulation. 6. Turn off the air outlet switch of the air-conditioning system on holidays and holidays, and ask the Public Works Department not to turn off the air-conditioning system air outlet switch to prevent condensation on the inner wall of the machine.

4. Requirements for daily inspection of temperature and humidity

* The inspection work is in charge of the SMT Engineering Section.

* The number of inspections is four times a day, divided into four time periods, namely 7:00-12:00; 12:00-19:00; 19:00-2:00; 2:00-7:00. (Twice each for day shift and night shift)

* The results of each inspection must be recorded in the prescribed form, and the name of the inspector must be signed.

* If the temperature and humidity value on the temperature and humidity record sheet is within the required range, write "OK" in the two columns of the/humidity condition> in the attached table. If it is found that the value is not within the required range, then Write "NG" and the corresponding temperature and humidity exceeding value in the corresponding column in the attached table, and notify the person in charge of the SMT engineering department immediately.

* The person in charge of the SMT engineering section should immediately notify the person in charge of the production section after receiving the notice. If necessary, stop the machine and notify the engineering section to check the air-conditioning system and humidity control system.

* After the temperature and humidity return to the required range, the person in charge of the SMT engineering section should immediately notify the production section to resume production.