Method for controlling temperature and humidity sensitive components in SMT factory
In order to ensure the correct use of temperature and humidity sensitive components during smt placement, and prevent smt placement components from being affected by moisture and humidity in the environment, use antistatic packaging materials. The following points can be effectively managed and controlled to avoid improper management And affect quality.
(1) Environmental regulation.
Temperature and humidity sensitive components use workshop environment temperature between 18 ~ 28 ℃, relative humidity between 40% ~ 60%; during storage, relative humidity of moisture-proof box <10%, temperature between 18 ~ 28 ℃; material staff every 4 hours Check the temperature and humidity of the moisture-proof box once and register its temperature and humidity value in the `` Temperature and Humidity Control Sheet ''; if the temperature and humidity exceed the specified range, immediately notify the relevant personnel to improve and take corresponding remedial measures (such as placing a desiccant, adjusting Room temperature or take out the components in the faulty moistureproof box and put them in a qualified moistureproof box). The open time or door opening time of the temperature and humidity environment space of each enclosed area should not exceed 5 minutes to ensure that the temperature and humidity conditions can continue to be within the control range.
(2) Process control.
a. When dismantling the vacuum packaging of humidity-sensitive components, the Smt patch production line must wear an electrostatic bracelet and electrostatic gloves, and open the vacuum packaging on a desktop with good static protection. After disassembly, check whether the humidity card changes meet the requirements (according to the label requirements on the packaging bag). For smt chip ICs that meet the requirements, put the "Humidity Sensitive Component Regulatory Label" on its packaging.
b. When the production line receives bulk moisture-sensitive components, it is necessary to confirm whether the components are qualified according to the "Humidity-sensitive Component Control Label", and priority is given to qualified components.
c. After the humidity sensitive component (IC) is unpacked, the exposure time in the air before re-soldering must not exceed the level and life of the humidity sensitive component.
d. For ICs that need to be baked and failed, hand them over to the QC staff for rejection and return them to the warehouse.
(3) Control methods
a. Incoming inspection ——— The desiccant bag and relative humidity card should be attached to the moisture-proof bag, and relevant text warning signs should be affixed outside the moisture-proof bag. If the packaging is not good, it needs to be confirmed and handled by relevant personnel.
b. Material storage—Unopened materials should be stored according to the instructions; if unopened materials need to be returned to storage, they should be sealed in a moisture-proof bag after baking; if unopened materials are not used immediately, put them in a low-temperature oven for temporary storage.
c. On-line operation-unpack when using, and check and fill the humidity indicator card; fill in the refueling control card and indicate the symbol of temperature and humidity sensitive components when refueling; return the materials according to the storage requirements after dehumidifying according to the storage requirements. Storage.
d. Dehumidification operation—Select baking conditions and time according to the humidity level of smt chip components, environmental conditions, and opening time.