Protection in anti-static production
1. The main process links in production
The main technological links in the production process of electronic products, the inspection of electrostatic sensitive devices in the factory, sophisticated screening and testing - distribution, inventory and storage - acceptance of ingredients - receipt, delivery, collection, return - pretreatment (including pretreatment Processing)—PCB assembly, insertion, welding—unipolar debugging—PCB loading into the machine—test run, observation (including high temperature aging)—inspection—prepackaging—intermediate processing—finished product shipment into warehouse , turnover, temporary storage, etc.
2. The process principle of establishing an electrostatic protection area (point)
(1) According to the electrostatic sensitivity of the devices used in the work area, it is divided into the first level, the second level, and the third level, and different protective measures are formulated according to different levels.
(2) According to the humidity situation in the area where the manufacturing plant is located, with reference to the annual average humidity, seasonal and monthly average humidity and the minimum humidity range, adopt corresponding effective protection techniques according to the conditions of lower than average humidity. When determining protective measures, special attention should be paid to the harmfulness of electrostatic high voltages that may be generated by the lowest humidity to sensitive devices.
(3) According to the actual measured electrostatic voltage data in the operating environment where the factory protection zone (point) is located, it should be used as the basis for adopting the protection level to make the protection level more appropriate.
(4) All the protection methods and measures selected in the electrostatic protection area (point) should be of less types, the lowest cost, and the effect can fully meet the protection requirements.
3. General requirements for electrostatic protection areas
(1) There are at most two entrances and exits in an electrostatic protection area, which are regarded as safety doors and placed in a conspicuous position at the door. There is a permanent safety area name plate with sunspots on a yellow background, and a permanent unified warning sign.
(2) The room temperature in the work area should be controlled between 15-20°C, and the relative humidity should be controlled between 50-70%.
(3) Instantaneous high-voltage sources or clockwise high-voltage operations should be avoided in the electrostatic protection area.
(4) The desktop, equipment, and human body must be safely grounded (that is, at zero potential). No ordinary plastic boards, plastic cloths, bakelite boards, rubber mats, etc. should be laid on the desktop for leakage of static electricity.
(5) It is forbidden to place non-productive items on the workbench, such as tableware and other items.
(6) The drawings and materials used by the operator should be put into a transparent anti-static plastic bag.
(7) Operators should wear anti-static work clothes, anti-static work shoes (socks), anti-static work gloves and work caps.
(8) Personnel in non-protected areas, when entering the production site with permission, should also wear anti-static work clothes and work shoes. In the production site, they are not allowed to touch SSD or PCB, and are not allowed to approach the operating personnel.
(9) The electrostatic protection area should avoid being set near the electromagnetic field of high-power radiation sources.
(10) The facilities in the static protection area shall be installed according to the static control method and process regulations determined by the production process.