What aspects should be paid attention to in pcba cleaning?

PCBA processing, in SMT and DIP plug-in soldering, the surface of the solder joints will be residual some flux rosin, etc.. The residue contains corrosive substances, residue in the pcba pad components above, may cause leakage, short circuit and thus affect the life of the product. The residue is dirty, does not meet the requirements of product cleanliness, so pcba needs to be cleaned before shipment. The following take you to understand the production process of pcba water washing some tips and precautions.

With the miniaturization of electronic products, electronic components density, small spacing, cleaning has become increasingly difficult, in the choice of which cleaning process, according to the type of solder paste and flux, the importance of the product, the customer’s requirements for cleaning quality to choose.

I. PCBA cleaning methods

1. Clean water cleaning: spray or dip wash

Clear water cleaning is to use deionized water, spray or dip wash, safe to use, dry after cleaning, this cleaning is cheap and safe, but some spoils are not easy to remove.

2. Semi-clean water cleaning

Semi-water cleaning is the use of organic solvents and deionized water, which adds some active agents, additives to form a cleaning agent, this cleaner contains organic solvents, low toxicity, the use of safer, but to rinse with water, and then dry.

3. Ultrasonic cleaning

The use of ultra-high frequency in the liquid medium into kinetic energy, the formation of countless small bubbles hitting the surface of the object, so that the surface of the dirt off, so as to achieve the effect of cleaning the dirt, very efficient, but also to reduce the electromagnetic interference.

II. PCBA cleaning technology requirements

1. PCBA surface welding components without special requirements, all products can be used to clean the PCBA board with special cleaning agents.

2. Some electronic components are prohibited from contacting the special cleaning agent, such as: key switches, network socket, buzzer, battery cells, LCD display, plastic components, lenses, etc..

3. The cleaning process, can not use tweezers and other metal direct contact PCBA, so as not to damage the PCBA board surface, scratch.

4. PCBA after components soldering, flux residue over time will produce corrosion physical reaction, should be cleaned as soon as possible.

5. PCBA cleaning is completed, should be placed in an oven of about 40-50 degrees, after 30 minutes of baking, and then remove the PCBA board after drying.

III. PCBA cleaning precautions

1. PCBA board surface can not be residual flux, tin beads and dross; surface and solder joints can not have whitish, gray phenomenon.

2. PCBA board surface can not be sticky; cleaning must wear electrostatic hand ring.

3. PCBA must wear a protective mask before cleaning.

4. has been cleaned PCBA board and not cleaned PCBA board placed separately and marked.

5. The cleaned PCBA board is prohibited to directly touch the surface with hands.