Importance of humidity control in production workshops of electronics factories

Most electronics should be operated and stored in dry conditions. According to statistics, more than a quarter of manufacturing defects in the world is correlated to the harm of moisture every year. For electronics, the harm of moisture has been one of the main factors affecting product quality

1、Integrated circuit (IC)

The harm of moisture to semiconductor industry is mainly manifested in the fact that moisture can enter IC via plastic packages from pins and other gaps to form hygroscopic phenomenon. Water vapor is formed during the heating in the SMT process, the pressure from which causes the cracking of IC resin package and cause the oxidation of internal metal of IC devices. Besides, in the process of welding the PCB of devices, cold solder will be caused due to the release of pressure from water vapor.
According to IPC-M190J-STD-033, the SMD elements that have been exposed to high-humidity environment should be placed in a drying oven with an RH below 10% for a time that is 10 times of the exposure duration, so as to restore their “floor life”, avoid scrapping and ensure safety.
2、Liquid crystal devices

Although the glass substrate, polarizer and filter of liquid crystal display (LCD) and other liquid crystal display are cleaned and dried in the production process, they may also be affected by moisture after cooling, which reduce the yield of products. Therefore, such devices should be placed in a dry environment with an RH below 40%.
3、Other electronic devices

Capacitors, ceramic devices, connectors, switches, solders, PCB, crystals, LED, silicon wafers, quartz oscillators, SMT adhesives, adhesives for electrode materials, electronic pastes, high-brightness devices and other devices may be affected by moisture.
4、Electronic devices in operation process

The semi-finished products in packaging to the next process, PCB before and after packaging to energization, IC, BGA, PCB and other elements not used up after unpacking, devices to be welded by the solder machine, devices to be reheated after baking and unpacked finished products may be affected by moisture.
5、Finished electronic machine may also be affected by moisture in storage process

If electronic machine is stored in high-humidity environment for a long time, failures will be caused. For computer board card CPU and other components, the goldfinger may be oxidized, causing poor contact and other failures. Electronic products should be produced and stored in an environment with a humidity below 40%. Some electronic products require lower humidity. Therefore, in order to prevent humid air from damaging electronic products and electronic parts and components, dehumidifiers and other devices that can lower air humidity must be used to remove the moist air to lower the air humidity to the most appropriate relative air humidity required for the workshop production and warehouse storage of electronic products and electronic parts and components.

Principle of rotary dehumidification：When humid air passes the treatment zone of the rotary wheel, steam is adsorbed by adsorption materials, and dry air is produced to deliver to the space required; the rotary wheel with steam runs slowly to enter the regeneration zone, high-temperature air adsorbed reversely is adsorbed and removed of moisture, the rotary wheel is recovered to regeneration adsorption, the humid and heating air is exhausted out of the workshop, and the rotary wheel regeneration is carried out repeatedly to ensure continuous operation of dehumidification. 

Application features of product

1. In-depth dehumidification, high efficiency

The PD-L series dehumidifier lowers moisture in air and treats ultra-low dew point below -70 degrees centigrade to satisfy air drying requirements required by low-dew point control.
2. Advanced equipment structure, high operation efficiency
Full welding is used for external structure of equipment to avoid system air leaking, ensure process requirements and lowering energy waste. Internal structure of the equipment is made of stainless steel to avoid individual composition corrosion in production and mechanical pollution to air process.
3. Flexible equipment configurations, complete project delivery
The PD-L series provide function requirement configurations flexibly:
a. Separate rotary wheel dehumidification functions or required air treatment sections;
b. Supporting refrigeration sources, direct or indirect refrigerant treatment process;
c.  Integrating automatic control for complete low dew-point drying system;
d.  Non-standard tailoring is adjusted subject to site conditions.
e.  Provide working rooms satisfy low dew-point structure requirements.
4. Low operation costs, saving energy consumption
The heating sources required for regeneration is supplied in form of electric heating, or steam or natural gas direct combustion, subject to user’s specific conditions. The PD-L series is added with energy recycling module to make user’s operation costs lower.
5. Long-term operation, easy maintenance
The rotary dehumidification system can be operated on a long-term basis without change of the moisture absorbent, and the mechanical parts are not provided with wearing parts frequently replaced. Its operation and maintenance is simple and reliable.