Design of cleaning process for highly reliable PCB components

- Aug 28, 2018-

Design of cleaning process

The cleaning conditions of electronic products manufacturers should meet the requirements of different types of flux in the solder. The best case is that the cleaning process required by the flux is just matching with the existing equipment and process. The production process must be in a controllable state to meet the harsh environmental requirements and the price is preferential.During the process optimization, the following aspects should be considered:

Assessment of contaminants

After a detailed understanding of the specific requirements/constraints of the components, the next step is to consider the assessment of pollutants, and the process should be considered from the following aspects:

· pollutant components

· physical characteristics

The number,

· process characteristics

· cleaning effect and associated conditions between cleaning equipment and cleaning procedures

· the cleaning process meeting the cleaning equipment and requirements


· assessment of materials

· assessment of pollutants

· development of validation program

· assessment of available cleaning techniques

· evaluation of production process

· implementation of the new process

· how to detect process problems

· process confirmation

Evaluation of materials

Development of a new cleaning technology, the first step to evaluate the component of the circuit board:

· component materials

Function of,

Components,

· size/geometry/structure

· operating points

· special requirements/constraints on parts

· compatibility of cleaning equipment with cleaning requirements

The material, size and geometric dimensions of the part will cause the cleaning space to be too small. For example, the "sandwich" part, when welded to the PCB, the distance between the bottom of the device and the PCB is small, and the flux residue is difficult to be cleaned (figure 1).During the cleaning process, the small and light parts usually need to be clamped or placed in basket (basket). The cleaning solution must be compatible with the components, PCB surface, metal coating, aluminum coating, label, handwriting and other materials. The special parts should consider whether they can withstand the cleaning.