Cleaning methods and requirements of the circuit board

Every PCB assembly manufacturer must adhere to proper cleaning standards. Now the appearance of the circuit board cleanliness requirements are more and more strict, without affecting the work of the board, our DYC factory has been working hard to deliver a clean circuit board to each customer。

1.Comply with IPC-5704
All medical device development must meet a specific set of quality control standards. Ipc-5704 is a set of standards specifically addressing cleanliness requirements for the manufacture of unassembled printed circuit boards. A large part of this needs to go through the necessary steps to prevent and remove any kind of ionic contamination or other unwanted debris from the Integrated Circuit board.

2.Ultrasonic cleaner
In terms of cleaning methods for prototype pcb assembly manufacturing, this method is the best. This is because ultrasonic cleaning involves a temperature-controlled process that is done at set time intervals. Of course, the solution used in this process will affect the ultimate effectiveness of the method.

3.Automatic cleaning machine
The process involves placing the soldering pcb board in a basket and dipping it into the solution. Once it is taken out of solution, it is then dried. However, it is important to choose a good solution so that any printed circuit board assembly material will not suffer any damage.

4.Manual cleaning
Although rarely used, there is an option to clean printed circuit boards by manual methods. The problem with this approach is that some areas are barely reachable, especially on smaller PCBs. However, for some components, such as the microphone, only the manual method can be used.

5.When extreme PCB cleanliness is required

SMT processing: If extreme cleanliness of bare boards (levels below 0.63μg/cm2, 4.0μg/in2) is required, it is best to design PCB parts with as few “exposed laminate” areas as possible. Ions tend to be easily washed off metal and solder mask surfaces but leave areas of the board that are not covered by plating or solder masks. This exposed laminate can cause ionic contamination, and the final board cleaning process can present challenges in removing these inclusions. These contaminants can now leak out during the ion chromatography test, affecting the results.