PCB ink FAQ (3)

Item

Question name

Phenomenon

Possible Causes

Countermeasures

11

Copper surface oxidation

To visualize the oxidation of the large copper surface below the ink into dark red

Too much baking time and temperature

Too much work or baking

Ink color is too light

Ink printing is too thin

Insufficient heat resistance of ink

Reduce baking time and temperature

Reduce the number of bake

Increase welding thickness

Adjust ink characteristics

12

Excessive corrosion

Visually or eyepiece after development Observe the white area of ​​the solder mask (larger than 1.5mil)

Ink printing is too thick

Insufficient exposure energy

Development temperature is too high

Too much developing pressure

Development time is too long

Negative film transmittance is too low

Insufficient time to stay

Exposure lamp expired

Exposure cooling quartz tube is dirty

10. Insufficient ink sensitivity

1. Confirm exposure job parameters

2. Confirm development job parameters

3. Reduce ink printing thickness

4. Increase dead time after exposure

5. Use better light transmittance worksheet

6. Confirm exposure lamp life

7. Adjust ink properties

13

Hole ink

After development, there is ink residue on the edge of the hole in the hole and it cannot be developed cleanly.

Bad printing alignment

Stencils shrink

Printing machine not used misplaced printing

Unscreened ink

Use empty screen printing

The stencil of the stencil is too small

Poor printing parameters

Pre-bake

Exposure point is too small

10. Exposure vacuum

11. Defective light shading on the exposure film

12. Poor development ability

13. Developer nozzle does not apply

1. Use stop screen

2. Dislocation function of printing machine

3. Need to scrape back ink

4. Confirm printing exposure tool specifications

5. Confirm pre-baking conditions and measure the temperature rise curve of each area

6. Adjust the shape of the developer nozzle and the spray height

7. Confirm development job parameters

8. Pay attention to autonomous inspection

14

Indentation of ink

Visually or visually observing the jagged surface of the non-neat welding edge

The substrate is non-UV resistant

Exposure film film surface production error

The shading rate of the exposed film shading area is poor

Use UV-proof substrate

Confirm the condition of the filmhead before exposure

Change the black film or negative film with better opacity

15

After the gold-welding stripping

The solder joints in the copper area or the wiring area are protected from soldering and copper surface separation

Over development

Insufficient exposure energy

Poor pre-treatment surface roughness

Premature stagnation causes the plate to oxidize

Baking time is too long or the temperature is too high

Chemical plant potion attacks too strong

Chemical plant operating parameters are poor

Bad ink resistance

Bad ink thickness

Check the pre-processing line to confirm whether it is in line with the standard quality of the process

Reduces plate stagnation time after pre-treatment

Confirm exposure development conditions

Confirm baking conditions

Change job flow

Replacement of gold chemical liquid

Confirmation of chemical plant operating parameters

Adjust ink characteristics

Source: Guangzhou Huitian Fine Chemical Co., Ltd.