Testing Method for PCB Etching Uniformity

1 Purpose

To inspect the uniformity of the outer layer etching lines

2 Testing Conditions

At room temperature

3 Testing Instruments

ISO Scope® MP30Copper Thickness Tester

4 Test Preparation

Take severalFR4 copper-clad boards, the surface must be clean and free of contaminants, specifications:1/1OZ,1.2mm~1.5mm, 18×24

5 Testing Steps

5.1Take1PCS test board and pass it through the etching machine at a certain speed, adjusting the transfer speed until the copper board is etched just enough to expose the substrate, while still leaving a certain amount of copper.

5.2Adjust the pressure distribution of each nozzle based on the condition of the board surface after etching, repeating the above experiment until the etching on both the upper and lower surfaces is uniform.

5.3Take1PCS test board, and on the upper and lower surfaces18″×24″ direction, take 10×8 points as shown in the attached diagram, measure and record the copper thickness at each point, then pass this board through the etching machine at a speed that etches the copper thickness to about 15-20um after drying, measure and record the etched copper thickness at the corresponding positions on the upper and lower surfaces.

5.4Calculate the etching amount range (R) of the copper thickness on the upper and lower surfaces, and create a surface plot of the etching amounts for both surfaces.

6 Testing Frequency and Evaluation

Process

Frequency

Evaluation

Outer Layer Etching

Etching Line

Once a month

≤5μm

Attached Diagram:

24 ″

0.6

1.0

3.0

3.0

3.0

3.0

3.0

3.0

3.0

1.0

0.6

0.6

1.0

3.0

3.0

3.0

1.0

0.6

Top View of Board Point Sampling (80 Points)

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