Some problems and how to control the PCB plug mechanism are what many people want to know, so this article brings you this knowledge.

First, the cause of the problem

With the continuous improvement of PCB manufacturers’ manufacturing precision, the manufacturers of via-hole circuit boards manufactured by PCB printed circuits are getting smaller and smaller. Regarding mechanically drilled production boards, through holes with a diameter of 0.3mm are normal, and 0.25mm or even 0.15mm is also infinite. As the aperture decreases, it is a lingering through-hole plug. After plugging the hole, the plate often breaks without breaking. The electrical measurement cannot measure the base, and finally flows into the client. After high temperature welding, thermal shock and even assembly, the application is only in East Window. It’s too late to reflect on it now!

If you can start from the manufacturing process, you can operate the hole plugs one by one to prevent bad clogging. This will be the best way to improve quality. I personally tried to discuss the mechanism of some plugs from the process, and provide some useful operation methods to prevent or reduce the occurrence of bad clogging.

Second, analyze the bad hole plugs in each process

We all know that PCB manufacturers have drilling, degumming, copper plating, plating, graphics processing, graphics plating and other major processes in PCB printed circuit board manufacturing and hole processing. Therefore, the resolution of the hole plug is also I will one by one. Introduce each process.

Drilling

The hole plugs caused by drilling mainly have the following types, and the object slices are shown in the figure below.

Summarize

Let’s sum it up: Despite this, my person is not very flat drilling. However, in reality, drilling is still one of the main incidents of bad plugging. According to the author’s statistical analysis, it is found that 35% of the holes do not have copper, and the hole plugging caused by drilling is very poor. Therefore, drilling control is the focus of poor plug control. I think the following aspects are the main control points:

1. According to the experimental results, rather than the traditional masters relying on apprenticeship experience to identify reasonable drilling parameters (the knife below is too fast and the plug is simple);

2. Timing adjustment of drilling rig;

3. Ensure dust collection;

4. It is important to know that the drill bit drills holes in the tape to bring the glue into the hole, rather than inserting the tape itself into the hole. Therefore, the drill should not be drilled on the tape at any time;

5. Develop useful methods to detect broken drill bits;

6. Many manufacturers have carried out high-pressure air dust collector pores and dust removal treatment after drilling, which can be implemented;

7. The deburring process before copper sinking should be ultrasonic washing and high-pressure washing (pressure above 50KG/CM2).