The classification and characteristic analysis of PCB hole-free copper

Classification and characteristics of hole-free copper

1. No copper in PTH hole: The electrical layer of the copper plate on the surface is uniform and normal, and the electrical layer of the plate in the hole is distributed evenly from the hole to the fracture. After the electrical connection, the fracture is covered by the electrical layer.

2. There is no copper in the copper thin hole of the board:

(1) There is no copper in the electrical copper thin holes of the whole board-the electrical layers of the surface copper and the hole copper plates are very thin. Figure electric layer encased;

(2) There is no copper in the thin hole of the electric copper in the hole-the electric layer of the surface copper plate is uniform and normal, and the electric layer of the hole in the hole shows a decreasing trend of sharpening from the hole to the fracture, and the fracture is generally in the middle of the hole. Copper layer left

The right has good uniformity and symmetry, and the fracture is covered by the electrical layer after the electrical image.

3. Repair broken holes:

(1) Copper inspection and repair broken holes-the electrical layer of the surface copper plate is uniform and normal, the electrical layer of the hole copper plate has no tendency to sharpen, and the fracture is irregular, which may appear in the hole or in the middle of the hole, and often appear on the hole wall Rough bumps and other defects, the fracture is covered by the electrical layer after the electrical connection.

(2) Corrosion inspection and repair of the concealed hole-the electrical layer of the surface copper plate is uniform and normal, the electrical layer of the hole copper plate has no tendency to sharpen, and the fracture is irregular, which may appear in the hole or in the middle of the hole, and often appears on the hole wall Rough bumps and other defects, the electrical layer at the fracture is not covered by the electrical layer of the board.

4. There is no copper in the plug hole: After the picture is electro-etched, there is obvious material stuck in the hole, most of the hole wall is etched away, and the picture electric layer at the fracture does not cover the electric layer of the board.

5. There is no copper in the electrical hole: the electrical layer at the fracture does not cover the electrical layer of the board-the thickness of the electrical layer and the electrical layer of the board are uniform, and the fracture is uniform; the electrical layer tends to sharpen until it disappears, and the electrical layer of the board The layer exceeds the electrical layer and continues to extend for a certain distance before being disconnected.

Improvement direction:

1. Operation (upper and lower board, parameter setting, maintenance, abnormal handling);

2. Equipment (crane, feeder, heating pen, vibration, pumping, filtration cycle);

3. Materials (plates, potions);

4. Methods (parameters, procedures, processes and quality control);

5. Environment (variation caused by dirty, messy and messy).

6. Measurement (medicine test, copper inspection and visual inspection).