one. Plating process classification:
Acid Bright Copper Plating Nickel/Gold Plating Tin
two. Process flow:
Pickling→Full Plate Copper Plating→Graphic Transfer→Acid Degreasing→Secondary Countercurrent Rinsing→Micro Etching→Secondary→Acid Pickling→Tin Plating→Secondary Countercurrent Rinsing
Countercurrent rinsing → pickling → pattern electroplating copper → secondary countercurrent rinsing → nickel plating → secondary rinsing → leaching citric acid → gold plating → recycling → 2-3 pure water washing → drying
three. Flow Description:
(I) Pickling
1 Role and purpose:
Removal of surface oxides, activation of the board surface, the general concentration of 5%, and some remain at about 10%, mainly to prevent the water into the bath caused by instability of sulfuric acid content;
2 The acid leaching time should not be too long to prevent the board surface from oxidizing. After using for a period of time, when the turbidity of the acid liquid or the copper content is too high, it should be replaced in time to prevent contamination of the surface of the electroplating copper cylinder and the board.
3 CP grade sulfuric acid should be used here;
(b) Full Plate Copper Plating: Also known as Copper, Panel, Panel-plating
1 Role and purpose:
Protecting the newly deposited thin chemical copper, preventing it from being etched by acid after oxidation, and adding it to a certain degree by electroplating
2 All-plate electroplating copper related process parameters: The main components of the bath are copper sulfate and sulfuric acid, using high acid and low copper recipes to ensure uniformity of plate surface thickness distribution during plating and deep plating capability for deep hole holes; At 180 g/L, more than 240 g/L; the content of copper sulfate is generally about 75 g/L, and a small amount of chloride ions are added to the bath solution, which acts as an auxiliary gloss agent and a copper photosensitizer to exert a gloss effect; The amount of light agent added or cylinder opening is generally 3-5ml/L. The addition of copper light agent is usually supplemented according to the method of kiloampere-hour or according to the actual production of plate effect; the current of the whole plate plating is generally calculated as 2A/square. Denomination is multiplied by the plating area on the board. For full board power, the board length dm × board width dm × 2 × 2A/DM2; copper cylinder temperature is maintained at room temperature, the general temperature does not exceed 32 degrees, multi-control At 22 degrees, so in the summer due to the temperature is too high, the copper cylinder is recommended to install a cooling temperature control system;
3 process maintenance:
Daily supplement of copper light agent according to 1000A hours, supplemented by 100-150ml/KAH; check the filter pump is working properly, with or without air leakage; apply a clean wet cloth to the cathode conductive rod every 2-3 hours Scrub clean; weekly analysis of copper sulfate copper sulfate (1 time/week), sulfuric acid (1 time/week), chloride ion (2 times/week) content, and adjust the photo-agent content by Hall tank test, and Timely replenish related raw materials; weekly cleaning anode rod, electric joints at both ends of the tank, timely replenish the anode copper ball in the titanium basket, electrolysis for 6-8 hours with low current 0.2-0.5ASD; monthly inspection Whether the titanium basket of the anode is damaged or not, and the damaged one should be replaced in time; check whether the anode mud is deposited on the bottom of the anode titanium basket; if any, clean it in time; use the carbon core to continuously filter for 6-8 hours; Every six months or so, depending on the status of the tank fluid, it is decided whether or not large treatment is required (activated carbon powder); the filter element of the filter pump must be replaced every two weeks;
4 major processing procedures: A. Take out the anode, pour out the anode, clean the anodic film on the anode surface, and then put it in the barrel of the copper anode, use a micro-etcher to roughen the copper corner surface to even pink, rinse and dry After loading into a titanium basket, place it in an acid bath for use. B. Store the anode titanium basket and anode bag in a 10% lye for 6-8 hours. Rinse and dry. Dilute with 5% dilute sulfuric acid. Rinse. Reserve
C. Transfer the bath liquid to the spare bath, add 1-3 ml/L of 30% hydrogen peroxide solution, start warming, wait until the temperature is added to about 65 degrees Celsius, turn on the air to stir, and keep warm air for 2-4 hours; D. turn off Stir the air and slowly dissolve the activated carbon powder into the bath by 3-5 g/L. After the solution is completely dissolved, turn on the air to stir and keep it warm for 2-4 hours. E. Turn off the air, stir, and warm the activated carbon. The powder slowly precipitates to the bottom of the tank; F. When the temperature drops to about 40 degrees, use a 10 um PP filter element to increase the filter tank solution to a clean working tank, turn on the air, stir it, place it in the anode, and hang it in the electrolytic plate. ,Press 0. 2-0. 5ASD current density low current electrolysis 6-8 hours, G. After laboratory analysis, adjust the content of sulfuric acid, copper sulfate, chloride ions in the tank to the normal operating range; According to the results of the Hall slot test to add H. After the plate surface color is uniform, the electrolysis can be stopped, and then 1-1. 5 ASD current density for electrolytic membrane processing 1-2 hours, until the anode generates a layer of uniform dense adhesion The black phosphorus film can be; I. trial plating OK.
5 The anode copper ball contains 0.3-0.6% phosphorus. The main purpose is to reduce the anode dissolution efficiency and reduce the copper powder generation.
6 When supplementing medicines, such as adding a large amount of copper sulfate, sulfuric acid; after the addition of low current electrolysis; additional sulfuric acid should pay attention to safety, when the amount of additional (10 liters or more) should be divided into several slow fill Addition; otherwise it will cause the bath temperature is too high, decomposition of photo-agent speed up, contaminate the bath;
7 The addition of chloride ions should pay special attention, because the chloride ion content is particularly low (30-90ppm), make sure that the cylinder or cup must be weighed accurately before adding; 1ml hydrochloric acid contains about 385ppm of chloride ions,
8 drug add formula:
Copper sulphate (unit: kg) = (75-X) x tank volume (l) / 1000
Sulfuric acid (unit: liter) = (10%-X) g/L x tank volume (l)
Or (Unit: liters) = (180-X) g/L × tank volume (l) / 1840
Hydrochloric acid (unit: ml) = (60-X) ppm x tank volume (l) / 385
(III) Acid Degreasing
1 Purpose and Function: Remove the oxide on the copper surface of the circuit and the remaining glue on the residual film of the ink to ensure the bonding force between the copper and the pattern electroplating copper or nickel.
2 Remember that using an acid degreasing agent here, why is it not an alkaline degreasing agent and the degreasing effect of the alkaline degreasing agent is better than an acid degreasing agent? The main reason is that the graphic ink is not resistant to alkali and can damage the graphics circuit. Therefore, only acid degreasing agent can be used before the pattern plating.
3 Only need to control the degreasing agent concentration and time during production, the degreasing agent concentration is about 10%, the time is guaranteed in 6 minutes, the time is slightly longer will not have bad influence; the use of the bath fluid replacement is also in accordance with 15 square meters / liter work Liquid, supplement added according to 100 square meters 0. 5-0. 8L;
(d) Microetching:
1 Purpose and Role: Clean the copper surface of the roughened line to ensure the bonding between the pattern electroplated copper and the primary copper
2 Sodium persulfate is used more often than sodium sulphite, the roughening rate is stable and uniform, and the water washability is good. The concentration of sodium persulfate is generally controlled at about 60 g/l, the time is controlled at about 20 seconds, and the medicine is added at 3-4 kilograms per 100 square meters. The copper content is controlled below 20g/l; other maintenance cylinders are the same with the copper sinking.
(v) Pickling
1 Role and purpose:
Removal of surface oxides, activation of the board surface, the general concentration of 5%, and some remain at about 10%, mainly to prevent the water into the bath caused by instability of sulfuric acid content;
2 The acid leaching time should not be too long to prevent the board surface from oxidizing. After using for a period of time, when the turbidity of the acid liquid or the copper content is too high, it should be replaced in time to prevent contamination of the surface of the electroplating copper cylinder and the board.
3 CP grade sulfuric acid should be used here;
(6) Electroplated copper: also called secondary copper, copper plating
1 Purpose and effect: In order to meet the rated current load of each line, the copper and copper of each line and hole need to reach a certain thickness, and the purpose of copper plating of the line is to thicken the hole copper and the line copper to a certain thickness in time;
2 other items are the same as full plate plating
Acid Bright Copper Plating Nickel/Gold Plating Tin
two. Process flow:
Pickling→Full Plate Copper Plating→Graphic Transfer→Acid Degreasing→Secondary Countercurrent Rinsing→Micro Etching→Secondary→Acid Pickling→Tin Plating→Secondary Countercurrent Rinsing
Countercurrent rinsing → pickling → pattern electroplating copper → secondary countercurrent rinsing → nickel plating → secondary rinsing → leaching citric acid → gold plating → recycling → 2-3 pure water washing → drying
three. Flow Description:
(I) Pickling
1 Role and purpose:
Removal of surface oxides, activation of the board surface, the general concentration of 5%, and some remain at about 10%, mainly to prevent the water into the bath caused by instability of sulfuric acid content;
2 The acid leaching time should not be too long to prevent the board surface from oxidizing. After using for a period of time, when the turbidity of the acid liquid or the copper content is too high, it should be replaced in time to prevent contamination of the surface of the electroplating copper cylinder and the board.
3 CP grade sulfuric acid should be used here;
(b) Full Plate Copper Plating: Also known as Copper, Panel, Panel-plating
1 Role and purpose:
Protecting the newly deposited thin chemical copper, preventing it from being etched by acid after oxidation, and adding it to a certain degree by electroplating
2 All-plate electroplating copper related process parameters: The main components of the bath are copper sulfate and sulfuric acid, using high acid and low copper recipes to ensure uniformity of plate surface thickness distribution during plating and deep plating capability for deep hole holes; At 180 g/L, more than 240 g/L; the content of copper sulfate is generally about 75 g/L, and a small amount of chloride ions are added to the bath solution, which acts as an auxiliary gloss agent and a copper photosensitizer to exert a gloss effect; The amount of light agent added or cylinder opening is generally 3-5ml/L. The addition of copper light agent is usually supplemented according to the method of kiloampere-hour or according to the actual production of plate effect; the current of the whole plate plating is generally calculated as 2A/square. Denomination is multiplied by the plating area on the board. For full board power, the board length dm × board width dm × 2 × 2A/DM2; copper cylinder temperature is maintained at room temperature, the general temperature does not exceed 32 degrees, multi-control At 22 degrees, so in the summer due to the temperature is too high, the copper cylinder is recommended to install a cooling temperature control system;
3 process maintenance:
Daily supplement of copper light agent according to 1000A hours, supplemented by 100-150ml/KAH; check the filter pump is working properly, with or without air leakage; apply a clean wet cloth to the cathode conductive rod every 2-3 hours Scrub clean; weekly analysis of copper sulfate copper sulfate (1 time/week), sulfuric acid (1 time/week), chloride ion (2 times/week) content, and adjust the photo-agent content by Hall tank test, and Timely replenish related raw materials; weekly cleaning anode rod, electric joints at both ends of the tank, timely replenish the anode copper ball in the titanium basket, electrolysis for 6-8 hours with low current 0.2-0.5ASD; monthly inspection Whether the titanium basket of the anode is damaged or not, and the damaged one should be replaced in time; check whether the anode mud is deposited on the bottom of the anode titanium basket; if any, clean it in time; use the carbon core to continuously filter for 6-8 hours; Every six months or so, depending on the status of the tank fluid, it is decided whether or not large treatment is required (activated carbon powder); the filter element of the filter pump must be replaced every two weeks;
4 major processing procedures: A. Take out the anode, pour out the anode, clean the anodic film on the anode surface, and then put it in the barrel of the copper anode, use a micro-etcher to roughen the copper corner surface to even pink, rinse and dry After loading into a titanium basket, place it in an acid bath for use. B. Store the anode titanium basket and anode bag in a 10% lye for 6-8 hours. Rinse and dry. Dilute with 5% dilute sulfuric acid. Rinse. Reserve
C. Transfer the bath liquid to the spare bath, add 1-3 ml/L of 30% hydrogen peroxide solution, start warming, wait until the temperature is added to about 65 degrees Celsius, turn on the air to stir, and keep warm air for 2-4 hours; D. turn off Stir the air and slowly dissolve the activated carbon powder into the bath by 3-5 g/L. After the solution is completely dissolved, turn on the air to stir and keep it warm for 2-4 hours. E. Turn off the air, stir, and warm the activated carbon. The powder slowly precipitates to the bottom of the tank; F. When the temperature drops to about 40 degrees, use a 10 um PP filter element to increase the filter tank solution to a clean working tank, turn on the air, stir it, place it in the anode, and hang it in the electrolytic plate. ,Press 0. 2-0. 5ASD current density low current electrolysis 6-8 hours, G. After laboratory analysis, adjust the content of sulfuric acid, copper sulfate, chloride ions in the tank to the normal operating range; According to the results of the Hall slot test to add H. After the plate surface color is uniform, the electrolysis can be stopped, and then 1-1. 5 ASD current density for electrolytic membrane processing 1-2 hours, until the anode generates a layer of uniform dense adhesion The black phosphorus film can be; I. trial plating OK.
5 The anode copper ball contains 0.3-0.6% phosphorus. The main purpose is to reduce the anode dissolution efficiency and reduce the copper powder generation.
6 When supplementing medicines, such as adding a large amount of copper sulfate, sulfuric acid; after the addition of low current electrolysis; additional sulfuric acid should pay attention to safety, when the amount of additional (10 liters or more) should be divided into several slow fill Addition; otherwise it will cause the bath temperature is too high, decomposition of photo-agent speed up, contaminate the bath;
7 The addition of chloride ions should pay special attention, because the chloride ion content is particularly low (30-90ppm), make sure that the cylinder or cup must be weighed accurately before adding; 1ml hydrochloric acid contains about 385ppm of chloride ions,
8 drug add formula:
Copper sulphate (unit: kg) = (75-X) x tank volume (l) / 1000
Sulfuric acid (unit: liter) = (10%-X) g/L x tank volume (l)
Or (Unit: liters) = (180-X) g/L × tank volume (l) / 1840
Hydrochloric acid (unit: ml) = (60-X) ppm x tank volume (l) / 385
(III) Acid Degreasing
1 Purpose and Function: Remove the oxide on the copper surface of the circuit and the remaining glue on the residual film of the ink to ensure the bonding force between the copper and the pattern electroplating copper or nickel.
2 Remember that using an acid degreasing agent here, why is it not an alkaline degreasing agent and the degreasing effect of the alkaline degreasing agent is better than an acid degreasing agent? The main reason is that the graphic ink is not resistant to alkali and can damage the graphics circuit. Therefore, only acid degreasing agent can be used before the pattern plating.
3 Only need to control the degreasing agent concentration and time during production, the degreasing agent concentration is about 10%, the time is guaranteed in 6 minutes, the time is slightly longer will not have bad influence; the use of the bath fluid replacement is also in accordance with 15 square meters / liter work Liquid, supplement added according to 100 square meters 0. 5-0. 8L;
(d) Microetching:
1 Purpose and Role: Clean the copper surface of the roughened line to ensure the bonding between the pattern electroplated copper and the primary copper
2 Sodium persulfate is used more often than sodium sulphite, the roughening rate is stable and uniform, and the water washability is good. The concentration of sodium persulfate is generally controlled at about 60 g/l, the time is controlled at about 20 seconds, and the medicine is added at 3-4 kilograms per 100 square meters. The copper content is controlled below 20g/l; other maintenance cylinders are the same with the copper sinking.
(v) Pickling
1 Role and purpose:
Removal of surface oxides, activation of the board surface, the general concentration of 5%, and some remain at about 10%, mainly to prevent the water into the bath caused by instability of sulfuric acid content;
2 The acid leaching time should not be too long to prevent the board surface from oxidizing. After using for a period of time, when the turbidity of the acid liquid or the copper content is too high, it should be replaced in time to prevent contamination of the surface of the electroplating copper cylinder and the board.
3 CP grade sulfuric acid should be used here;
(6) Electroplated copper: also called secondary copper, copper plating
1 Purpose and effect: In order to meet the rated current load of each line, the copper and copper of each line and hole need to reach a certain thickness, and the purpose of copper plating of the line is to thicken the hole copper and the line copper to a certain thickness in time;
2 other items are the same as full plate plating