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Poor plating solution

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coating quality Most of the bad occurrences are plating conditions,Abnormal plating equipment or plating solution,and human negligence.It is often easier to find the cause to overcome when a bad situation occurs in the field,But it’s tricky after a period of plating..However Acid and gas in the future,Oxygen ,< /span>Moisture, etc.,Accelerate oxidative corrosion must also be noted.The following chapter will be Explain the cause of the poor plating and the countermeasures for improvement.

1. Rough surface: refers to uneven, non-bright surface, usually rough and white

(1) Possible causes:   (2) Improvement measures:

  1. The surface of the material is severely rough, and the coating cannot cover the flat. 1. If the material is severely rough, stop production immediately and notify the customer.

  2. The metal transmission wheel has a rough surface and is too tightly pressed to cause crushing. 2. If the transmission wheel is rough, you can use it and check the tightness.

  3. The current density is slightly higher, some surfaces are not bright and rough (not burnt) 3. Calculate whether the current density is too high, if it should reduce the current

  4. Bath temperature is too low, generally nickel plating will occur) 4. Wait for the sharpness to rise and then turn on, or reduce the current, and immediately check the temperature control system.

  5.PH value is too high or too low, generally nickel plating or gold plating (too low) will occur. 5. Immediately adjust the PH to the standard range.

  6.Pre-treatment liquid corrosion substrate. 6.Check the pre-treatment agent, dilute the agent or replace the agent

2. Adhesive foreign matter: refers to the dirt attached to the surface of the terminal.

(1) Possible causes:   (2) Improvement measures:

1. The water is not clean or the water quality is bad (if there are micro bacteria). 1. Clean the sink and replace it with new water.

2. Occupy mechanical oil pollution in the receiving system. 2. There will be oil stains to cover.

3. The material has a similar gel and cannot be removed in the pre-treatment process. 3. The solvent must be soaked first.

4. When the material is collected, it will be stained with dirt. 4. Avoid landing. If the soil has been smeared with air and it can be cleaned with a lot of soaking, it is recommended to clean it again.

5. Tin-lead crystals adhere to   5. Immediately remove crystals.

6 brush plating wool? Fiber silk 6. Replace wool? Check the contact pressure.

7. Paper tape dissolves the fiber. 7. Clearing the groove.

8. Belt off-chip. 8.Replace the belt.

3. Poor adhesion: refers to the phenomenon of peeling, peeling, foaming, etc. of the coating.

(1) Possible causes:  (2). Improvement measures:

1. Poor pre-treatment, such as stripping nickel. 1. Strengthen pre-treatment.

2. Cathodic contact with poor discharge, such as nickel stripping, nickel stripping, nickel   stripping lead.  2. Check the cathode for poor contact, adjust in time.

3. The plating solution is seriously polluted. 3.Change the potion

4. The production rate is too slow, and the bottom layer is oxidized again, such as nickel. The layer is oxidized in the gold bath (or gold reduction), stripped of lead and lead.  4, must be activated again before plating.

5. Washing is not clean. 5. Replace with new water and clean the sink if necessary.

6. The material is seriously oxidized, such as oxidized plaque, oxide film after heat treatment. 6. The rust and deoxidation film must be treated first, usually by chemical polishing or electrolytic polishing.

7. Stop the chemical replacement reaction caused. 7. It must be stopped or cut off defective products

8, the operating voltage is too high, the cathode conductive head and the plated parts generate heat, causing the oxidation of the coating.   8. Reduce the operating voltage or check the wire contact conditions

9, the bottom plating is poor (such as charring), causing the next layer to peel off. 9. Improve the quality of the underlying plating.

10. Severe. Scraping formed by charring 10. Refer to NO12 treatment countermeasures.

4. Dew copper: It can be clearly seen in copper or yellow black at low current (in the groove)

(1) Possible causes:   (2) Improvement measures:

1. Poor pre-treatment, grease, oxides. Foreign matter has not been removed, plating can not be precipitated. 1. Strengthen pre-treatment or reduce production rate

2. The operating current density is too low, resulting in a low current region, the plating layer cannot be precipitated. 2. Recalculating the plating conditions.

3 Excessive nickel brightener, resulting in low current zone, the coating can not be precipitated 3. Treat the syrup, remove too much brightener or update.

4. Serious scratching causes copper exposure. 4. Check the plating process (check NO5)

5. Not plated. 5. Adjust current position.

5 scratches: refers to horizontal lines, generally easier to occur in tin-lead plating.

(1) Possible causes:   (2) Improvement measures:

1. The material itself is in the process of stamping, and causes scratches. 1. Stop production, and contact customer.

  2. Metallic tools in the electroplating equipment are scratched, such as cathode heads, oven locators, guide wheels, etc. 2. Check the plating process and adjust the equipment and tools in a timely manner.

  3. Scratch by electroplated crystals. 3. Stop production and immediately remove crystals.

6. Deformation (scraping): The shape of the terminal has deviated from the original size or position.

(1) Possible causes:   (2) Improvement measures:

1. The material itself is deformed during stamping or transportation. 1. Stop production and wait for contact with customers.

  2. Electroplated equipment, manufacturing scraping (such as blowing. Positioner, oscillator, notch, slewing wheel) 2. Check the plating process, adjust equipment and tools in time.

  3. The plate is too small or poorly wounded, causing scraping when entering the material 3. Stop production and adjust the plate at the right time

  4.Drive wheel change, 4.Correct the drive wheel or change the drive mode.

7 crush injury: refers to the irregular shape of the hole

Possible reasons:   Improve countermeasures:

1) It has been crushed during the processing of the punching machine, and the coating cannot cover the flat layer

2) The drive wheel is loose or malfunctioning, causing injury when pressing. 1) Stop production and wait for contact with customers

2) Check the transmission mechanism or replace the spare parts

8 White fog: refers to the surface of the coating is a cloud, not bright but flat.

Possible causes: 1) Poor pretreatment

2) The plating solution is contaminated      

3) The tin-lead layer is loved by acid corrosion, such as corrosion by tin-lead solution during shutdown.

4) The temperature of tin and lead syrup is too high   

5) Tin-lead current density is too low

6) Insufficient gloss agent       

7) Passing the force wheel is dirty

8) Tin-lead electricity is long-lasting, resulting in foam adhesion. Improvement measures: 1) Strengthening pre-treatment

2) Change the syrup and purify the contaminated fluid

3) Avoid downtime, if it is unavoidable, cut off poorly

4) Immediately check the temperature control system and reset the temperature

5) Increase current density

6) Make up the trapping agent drive wheel

7) Clean the drive wheel

8) Immediately remove the foam

9 pinholes: refers to groups, small round holes (like bell-shaped) 

Possible reasons:   Improve countermeasures:

1. The current density of the operation is too low. 1. Reduce the current density

2. The surface tension of the plating solution is too large and the humectant is insufficient.   2. Add moisturizer, or check the potion.

3. Plating time mixing effect is poor.   3. Strengthen the mixing.

4. Tin bath temperature is too low   4. Adjust bath temperature

5. Electroplating syrup is contaminated.  5. Purify the potion or update.

6. Poor pretreatment.  6. Strengthen the pre-treatment effect.

 

10. Tin-lead remelting: The surface of the coating is as plain as a hill (like foaming, but good adhesion), and only tin-lead plating will occur.

(1) Possible causes:   (2) Improvement measures:

1. The tin-lead cathode is overheated (the voltage is too high), causing the tin-lead layer to re-melt.   1. Reduce the voltage and understand why the bath voltage is too high, and correct the plating conditions.

  2. The oven temperature is too high, and the baking time is too long, resulting in remelting of the tin-lead layer.   2. Reduce the oven temperature and check the temperature control system.

 

11. Terminal melting: refers to the surface of the surface is heated into a concave shape, usually caused by copper material (before nickel plating) or tin-lead plating.

(1) Possible causes:   (2) Improvement measures:

1. The cathode contact between nickel plating or tin-lead plating is poor, and the discharge spark melts the copper into a cavity.   1. Check the cathode and adjust it at the appropriate time.

 

12. Coating burnt: The surface of the coating is severely dark and rough, such as carbon. (refers to the high current density zone)

(1) Possible causes:   (2) Improvement measures:

1. The operating current density is too high.   1. Reduce current density.

2. The bath temperature is too low.   2. Increase the bath temperature and check the temperature control system.

3. Poor mixing.   3. Increase the mixing effect.

4. Insufficient gloss.  4. Make up the gloss.

5. The pH is too high.  5. Correct the PH value to the standard range.

6. The plating position is improper. (Electronic flow curve) 6. Re-correct the plating position and pay attention to the current distribution line.

7. Rectifier filter is poor.  7. Check if the filter is in compliance with the standard. If the offset is necessary, the rectifier must be repaired.

 

13. The plating thickness is too high: it means that the actual plating thickness exceeds the expected thickness.

(1) Possible causes:   (2) Improvement measures:

1. The transmission speed is slow, not accurate or the speed is unstable.   1. Check the transmission system to correct the production rate.

2. The current is too high, not allowed or the current is unstable.   2. Check the rectifier and anode and cathode, and correct it in time.

3. Select the plating position variation.   3. Check whether the plating position is deviated and readjust.

4. The metal concentration of the syrup is increased, and the gold plating is generally sensitive.   4. Adjust the current or drive speed.

5. The PH value of the potion is too high.   5. Adjust the pH to the standard range.

6. The fluorescent film thickness tester deviates, or the test method is wrong.  6. Calibrate the instrument or determine the test method.

7. The bath temperature is high.  7. Check the temperature control system.

 

 

14. Insufficient plating thickness: the actual thickness of the plated film is lower than the expected thickness

(1) Possible causes:   (2) Improvement measures:

1. The transmission speed becomes faster, not accurate or the speed is unstable.   1. Check the transmission system to correct the production rate.

2. The current is too low, not allowed or the current is unstable.   2. Check the rectifier and anode and cathode, and correct it in time.

3. Select the plating position variation.   3. Check whether the plating position is deviated and readjust.

4. The metal concentration of the syrup is lowered, or the syrup is diluted.  4. Adjust the current or transmission speed, and stop production if necessary.

5. The PH value of the syrup is low.   5. Adjust the pH to the standard range.

6. The fluorescent film thickness tester deviates, or the test method is wrong.  6. Calibrate the instrument or determine the test method.

7. The bath temperature is low.  7. Check the temperature control system and stop production if necessary.

8. There is gold in the plating structure, which consumes part of the current.   8. Remove gold deposits or replace the tool.

9. Electroplating syrup stirring, uneven circulation or metal replenishment is not enough.  9. Improve the circulation or supplementation of the syrup.

 

15. Uneven plating thickness: It means that the actual plating film thickness is high and low, or unevenly distributed.

(1) Possible causes:   (2) Improvement measures:

1. The transmission speed is unstable.   1. Check the transmission system to correct the production rate.

2. The current is unstable.   2. Check the rectifier and anode and cathode, and correct it in time.

3. The terminal is severely deformed, resulting in unstable plating position.  3. Check whether the plating position is deviated. If the material cannot be improved due to severe deformation process, it must be stopped.

4. The terminal structure causes uneven distribution of high and low currents.   4. Adjust the plating position and increase the mixing effect.

5. Poor mixing effect.  5. Increase the mixing effect.

6. There is a problem with the film thickness test position, resulting in large errors.  6. The test position must be reworked.

7. The plating mechanism is unstable.  7. Improve the plating mechanism.

 

16. The coating is dark red: usually the golden color is dark and reddish.

(1) Possible causes:   (2) Improvement measures:

1. Gold plating syrup deviates.   1. Re-adjust the plating solution.

2. The coating is rough, and the white layer is covered with red and red.   2. Improve the nickel layer.

3. Washing water is not clean, causing erythema.   3. Replace the washing water.

4. The plated parts are not completely dry and will oxidize red in the future.  4. Check the drying system to determine that the plated parts are dry and the reddish terminals can be cleaned with dilute cyanide.

 

17. Interface black line, fog line: This phenomenon usually occurs at the interface of the semi-tin-plated lead layer.

(1) Possible causes:   (2) Improvement measures:

1. The cathode reaction is too large, and a large amount of hydrogen foam floats on the liquid surface.   1. Reduce the current.

2. Poor cathode stirring.   2. Adjust the frequency and amplitude of the oscillator.

3. The plating height is not adjusted uniformly.   3. Check the plating height and re-correct.

4. Poor design of the plating tank, causing the foam to remain in the plating bath surface and cannot be eliminated.   4. Improve the plating structure.

5. Tin-lead syrup low-current zone white fog.  5. Correct tin-lead syrup to the best tank condition.

6. Rectifier filter is poor.  6. Measure the filter with an oscilloscope to determine the fault when the filter is poor, and repair the rectifier.

 

18. Poor soldering: Refers to the poor tin-lead coating of tin-lead coating.

(1) Possible causes:   (2) Improvement measures:

1. The tin-lead plating solution is contaminated.   1. Replace tin and lead syrup.

2. Excessive amount of gloss agent, resulting in excessive carbon content of the coating.  2. Immediately do activated carbon filtration, or replace the potion.

3.  Poor treatment after plating (residual acid, poor water quality, salt formation, foreign matter adhesion).  3. Improve processes and improve water quality

4. Bad adhesions   4. Solve the problem of poor adhesion.

5. The voltage is too high during electroplating, causing the plated parts to be thermally oxidized and passivated. 5. Improve the conductive equipment.

6. The current density is too high, resulting in poor plating structure.  6. Reduce the current density.

7. Poor mixing results in poor plating structure.  7. Increase the mixing effect.

8. The bath temperature is too high, resulting in poor plating structure.   8. Immediately lower the bath temperature and check the cooling system.

9. The coating is poorly placed and the time is too long, causing oxidation and aging of the coating.  9. Strengthen packaging and improve storage environment.

10. The coating is too thin   10. Increase the thickness of the plating layer.

11. The solder temperature is incorrect.  11. Check the solder temperature.

12. Influence of the shape of the plated part.  12. Change the judgment method.

13. The flux is too high.  13. Replace the flux.

14. Influence of plating material (tin > tin lead > gold > copper > phosphor bronze > brass)   14. Explore materials.

15. There are foreign objects on the surface of the plated parts, such as oil stains.  15. Remove foreign matter.

16. The bottom layer is rough.  16. Improve the underlying flatness.

 

19. Blackening of the coating: Black lines that do not contain charred black and tin-lead interfaces.

(1) Possible causes:   (2) Improvement measures:

1. Tin-lead plating has been white mist and will turn black in the future.  1. Refer to the eighth, the countermeasures to deal with tin-lead white fog.

2. The nickel bath has been contaminated and there will be black plating in the low current zone.  2. Do activated carbon treatment, or weak electrolytic treatment.

3. The plated parts are severely blackened by oxidation.  3. Analyze the cause.

4. Shutdown causes corrosion or reduction.  4. Cut out bad and avoid downtime.

5. The tin-lead coating is blackened by the spark released by the cathode conductive head.  5. Adjust the cathode contact head to make good contact with the terminal.

 

20. Tin slag: refers to the tin-lead metal on the surface of the tin-lead layer with intermittent fineness, usually with the most material.

(1) Possible causes:   (2) Improvement measures:

1. Tin-lead syrup brings out crystallization at the cathode conduction seat.  1. Improve the delivery of potions and strengthen the cleaning process.

2. Rub in the oven and scrape off the high temperature metal.  2. Adjust the tool in the oven to avoid rubbing to the terminal and adjust the oven temperature.