First of all, SMT production equipment such as force front reflow soldering, force front wave soldering, force front paste printing press and pasteThe installation must be well grounded, and the SMT w...
First of all, SMT production equipment such as force front reflow soldering, force front wave soldering, force front paste printing press and paste
The installation must be well grounded, and the SMT workshop should adopt three-phase five-wire grounding method and independent grounding. The ground of production place, work mesa mat, seat should meet antistatic requirement. Maintain constant temperature and humidity in the workshop. It should be equipped with anti-static electric box, revolving box, PCB frame, logistics trolley, antistatic packaging belt, antistatic wrist strap, anti-static soldering iron and tools.
(1) the anti-static area is set up according to the anti-static requirement, and there are obvious anti-static warning signs. The electrostatic sensitivity of the device used in the operating area is divided into 1, 2 and 3 levels, and different protective measures are developed according to different levels.
Class 1 static sensitivity range: 0-1999v 2 class electrostatic sensitivity range: 2000-3999v 3 class electrostatic sensitivity range: 4000-15999V 16000V above non-electrostatic sensitive products.
(2) the electrostatic safety zone (point) at room temperature for 23 + / - 3 ℃, relative humidity of 45-70% RH. It is prohibited to operate SSD (electrostatic sensitive components) in less than 30% of the environment. (3) regularly measure surface resistance values of surface, desktop and turnover box.
(4) the static safety zone (point) is prohibited from placing non-productive items such as tableware, tea sets, bags, wool fabrics, newspapers, rubber gloves, etc.
(5) workers enter the anti-static area and need to discharge. Operators must wear overalls and antistatic shoes and stockings when operating. The safety inspection must be done before the operation.
(6) wear anti-static wristbands when operating, and measure the band's effectiveness every day.
(7) when testing SSD, take one piece from the box, tube and plate, measure one piece, place one piece, and do not pile on the table. The rejected devices should be rejected.
(8) the electrical and electrical sequence of the test must be followed: low voltage, high voltage, signal voltage sequence. The order of electricity goes the other way. The power supply voltage must not exceed the rating.
(9) the inspector should be familiar with the type, variety and testing knowledge of SSD, and understand the basic knowledge of electrostatic protection.
10. Electrostatic sensitive components (SSDS) transportation, storage and use requirements
(1) the SSD shall not fall to the ground during the transportation process, and shall not be free from the packaging.
(2) the relative humidity of storeroom of SSD storage: 30-40% RH.
(3) maintain the original packaging during SSD storage, and use a container with anti-static performance if the packaging is to be replaced.
(4) in the warehouse, anti-static labels should be attached to the position of SSD devices.
(5) the method of visual measurement of SSD devices is used to check the quantity of the original packaging of SSD devices. (6) when writing, erasing and protecting the EPROM, the writer/eraser should be fully grounded and should be protected with anti-static bracelet.
(7) operators of assembly, welding, repair board and commissioning must operate strictly according to the requirements of electrostatic protection.
(8) test and verify qualified printed circuit boards are sprayed with ion gun before packaging to eliminate the static charge that may accumulate.
11. Anti - static working area management and maintenance
(1) develop anti-static management system and be responsible for it.
(2) standby antistatic work clothes, shoes, bracelets and other personal items for use by foreign personnel.
(3) regularly maintain and check the effectiveness of anti-static facilities.
(4) the wrist band is checked once a week (or daily).
(5) the grounding of table mat, ground pad and electrostatic eliminator are checked once a month.
(6) anti-static components rack, printing plate rack and circulating box; The anti-static performance of transporters, table MATS and floor MATS is checked every six months.