PCB Tech - ​Anti-static requirements for PCBA processing and production

Workshop anti-static requirements

According to the requirements of PCBA product production level, the production workshop should be equipped with corresponding anti-static facilities, and the ground wire should be independent and reliable. Keep constant temperature and humidity in the workshop. Separate static safe working areas, and affix obvious anti-static warning signs.

The grounding system outside the workshop is inspected once a year, and the grounding systems such as the floor/mat, workbench, etc. of the workshop are inspected once every six months, and corresponding records shall be made.

The temperature and humidity in the workshop are respectively controlled at (25±2) degree Celsius and 65%±5%RH; measure twice a day and make corresponding records.

Statutory protection requirements for employees

When entering the anti-static area, you must wear anti-static overalls and anti-static shoes as required;

Before touching electrostatic sensitive components, you must wear a grounding wrist strap or grounding foot strap as required, and pass the corresponding electrostatic test;

Articles prone to static electricity are not allowed to be brought into the anti-static area;

The handling, storage and distribution of electrostatic sensitive components must be stored in anti-static packaging;

The anti-static package can only be opened after the corresponding anti-static measures have been taken;

Trolleys and shelves used in anti-static areas must have proper grounding devices;

Anti-static work clothes and work shoes are prohibited from being worn out of the work area, and cleaned regularly according to regulations;

The cleaning of the anti-static work surface must use a cleaning agent approved by the electrostatic protection personnel;

Avoid placing static sensitive components and circuit boards with plastic products or tools (such as computers and computer terminals);

Connect all tools and machines to the ground;

Use static protection table mats;

Employees without wristbands approach the static protection workstation;

Immediately report all possible causes of electrostatic damage.

Matters needing attention during operation

Touch the work surface with both hands before holding the PCBA component, so that the static electricity on your hands is transmitted to the ground through the anti-static work surface;

Place the device pins down on a table that dissipates static electricity;

When holding an integrated circuit, you should grasp the body of the integrated block, not the pins;

When operating electronic components, they should be held at the edge of the PCB, and do not directly touch the components or the circuit on the board;

Do not drag or slide electronic components on any surface;

The non-conductor should keep a distance of more than 1m from the static safe working area;

Take out the components and circuit boards from the anti-static packaging box only in the static safe working area;

Place the static sensitive components that are not in use temporarily in an antistatic container or packaging box;

Reduce the number of handling to the limit.

Anti-static requirements of other relevant departments

Design department

The design department should be familiar with the types, models, technical performance and protection requirements of SSDs, and choose ICs with electrostatic protection as much as possible. In circuit design, the application of electrostatic suppression technology, such as electrostatic shielding and grounding technology, should be considered. Warning symbols must be included in the preparation of design files containing SSD. The main design documents involved are: instruction manual (user manual), technical manual, detailed list, PCB diagram (lead-out end processing), assembly drawing and debugging, inspection instructions (including SSD inspection in the factory).

craft department

When conducting a process review of the design, the relevant content of the design documents should be reviewed; the special process documents, guidance documents and related systems for the anti-static project should be compiled; Application and precautions of anti-static equipment.

Material department

When there are SSDs in the outsourcing summary table, the manufacturer should be selected together with the design and process departments. The packaging of the SSD and the anti-static requirements during transportation should be clarified when supplying.

Inspection department

Check if the package of SSD device is complete. SSD testing and aging screening should be carried out in static safe areas, and operators should wear anti-static overalls/shoes.