Most of the electronic products are required to work and store under dry conditions. According to statistics, there are more than 1/4 in the world every year, which are related to the harm of humidity. For the electronics industry, the harm of moisture has become one of the main factors that affect the quality of the products.
(1) integrated circuit: the harm of humidity to semiconductor industry is mainly manifested in the humidity can penetrate into the IC through IC plastic packaging and from the gap such as pins, resulting in IC moisture absorption.
Water vapor is formed during the heating process of the SMT process, resulting in the cracking of the IC resin package and the oxidation of the internal metal in the IC device, resulting in the product failure. In addition, when the device is in the welding process of PCB plate, because the water vapor pressure release, will also lead to.
According to the IPC-M190 J-STD-033 standard, the SMD components exposed to high humidity air environment must be placed in the drying chamber below 10%RH humidity for 10 times of exposure time, so as to restore the "workshop life" of the components, avoid scrapping and ensure safety.
(2) liquid crystal devices: liquid crystal display and other LCD devices, such as glass substrate and polarizer and filter, should be cleaned and dried in the production process. However, when they are cooled down, they will still be affected by moisture and reduce the pass rate of products. Therefore, after cleaning and drying, it should be stored in a dry environment below 40%RH.
(3) other electronic devices: capacitors, ceramic devices, connectors, switches, solders, PCB, crystals, silicon wafers, quartz oscillators, SMT adhesives, electrode material adhesives, electronic paste and high brightness devices will all be dampness.
(4) electronic devices during the operation of the semi-finished products in the package to the next procedure; PCB package before and after package to electricity; after unpacking but not yet finished using IC, BGA, PCB and other devices; for tin welding; baking temperature returning device to be completed; no packaging production the finished product, will be wet damage.
(5) the finished electronic machine will also be dampness in the process of storage. If the storage time is too long in high humidity environment, it will cause failure. For computer card CPU, it will cause oxidation of gold finger and cause bad contact.
The humidity of the production of the electronic industry and the storage environment of the products should be below 40%. Some varieties also require lower humidity.