Detailed explanation of PCBA baking conditions and specifications

Detailed explanation of PCBA baking conditions and specifications

PCB manufacturers and PCB designers explain PCBA baking conditions and specifications

1、 Notice on PCBA baking:

For devices that are no longer used after repair, in principle, the PCBA module will not be baked and dehumidified. However, if the whole board needs to be heated to more than 110 ℃ during repair, or if there are other moisture sensitive devices within 0.5cm around the repair work area, the PCBA module must be pre baked and dehumidified according to the requirements of the humidity sensitivity level and storage conditions. If the PCBA contains plug-in electrolytic capacitors, it must be baked in a convection oven at low temperature. If there is no plug-in electrolytic capacitor, high temperature baking can be used.

2、 PCBA baking conditions

At the same time, for the moisture sensitive devices reused after repair, if the hot air reflow, infrared and other repair processes are used to heat the solder joints through the device package, the PCBA components must be baked at low temperature according to the requirements of the moisture sensitivity level and storage conditions of the repaired devices; For the repair process using manual soldering iron to heat solder joints, it is unnecessary to pre bake the humidity sensor under the premise that the heating process is controlled.

The requirements for heating times of PCBA and device repair differ from the requirements for cumulative heating times of PCBA and device repair. The allowable repair heating times of PCBA components with the same tag number shall not exceed 4 times; The allowable repair heating times of the device shall not exceed 5 times. If the repair heating times are exceeded, it is not recommended to send it to the customer again, but it can be used for testing, because the reliability of the components and devices drops sharply.

When the PCBA is double-sided SMT reflow soldering, and the time difference between the first and second side production exceeds the unpacking service life of the humidity sensitive element on the first side, the PCBA that completes the first side SMT must be baked before continuing the second side SMT production.

3、 PCBA baking requirements:

1. Each shift shall first check whether the temperature and humidity of material storage are within the required range every day (if there is any abnormality, it shall be fed back and handled in time)

2. Untrained personnel are not allowed to work.

3. In case of any abnormality during the operation, notify the engineering technicians in time.

4. When contacting materials, electrostatic protection must be done and electrostatic gloves must be worn.

5. Lead and lead-free materials shall be stored and baked separately.

6. After baking, wait until the components and materials are completely cooled to room temperature before vacuum packaging or online use.

4、 Attachment: Precautions for PCBA baking:

1. Wear gloves when contacting PCBA.

2. Do not bake over time.

3. The PCAB that has completed baking shall be cooled to room temperature before it can be put online.