KR20030006809A - Composite in order to recycle etchant which can continuously operate and supply, and the supply method - Google Patents

Abstract

PURPOSE: An etching solution generating composition for continuous work and supply, a method for supplying HCl as an oxidation auxiliary, and a method for supplying the etching solution are provided, to allow the CuCl2-NaClO3 etching solution for the formation of a PCB circuit to be worked continuously. CONSTITUTION: The etching solution generating composition comprises 150-250 g/L of NaClO3 as an oxidizing agent; 40-60 g/L of an additive; and deionized water. Preferably the additive is at least one selected from the group consisting of 0.5-1.5 wt% of a corrosion preventer comprising 1,2,3-benzotriazole and/or polytriazole, 1-3 wt% of an exfoliation promoter, 0.1 wt% of a surfactant comprising dilute alcohol alkoxylate or a block copolymer of ethylene oxide and propylene oxide, and 0.3 wt% of an amine. 35% HCl is supplied as an oxidation auxiliary by the ratio of the generating composition to the HCl solution being 1 : 1.3-1.5.

Description

Composition in order to recycle etching work solution for continuous operation and supply {Composite in order to recycle etchant which can continuously operate and supply, and the supply method}

The present invention relates to a corrosion etching solution, and more particularly, to a regenerated composition of an etching working solution for forming a copper chloride-sodium chloride-based PCB circuit capable of a continuous process and a supply method thereof.

Conventionally, H ₂ O ₂ -based corrosion solutions are generally used for panel corrosion, and H ₂ O _{2 and} HCl are the main raw materials, and continuous operation is possible by controlling specific gravity or redox potential difference (ORP).

In addition, the development of a regeneration system resulted in reduced waste and economic feasibility. The Ferric Chloride method is widely used for sectional corrosion and is being replaced by copper chloride.

Alkaline (Ammonia) corrosion solution, which is recently used for the development of stabilizers for fine line etching and is increasing in usage, is used for pattern corrosion. It is widely used because of its merits in producing products, and it solved some of the environmental problems by developing regeneration devices.

Other hydrogen peroxide / sulfuric acid corrosion solutions and ammonium persulphate etchants were present. However, these conventional corrosion etchant products have the following problems in common.

1) The amount of copper dissolved is very low. (120 ~ 130 g / ℓ)

2) high HCl concentration (pH 1.3 to 1.5),

3) There is a risk of explosion

4) The price is expensive

5) Causes dry film adhesion problems and edge defects after development.

6) The solution is unstable and cannot be used as it is after being left for a long time.

7) Large amount of waste liquid

8) The corrosion rate is bad, so fine pattern etching is impossible.

Therefore, the copper dissolution rate of the conventional PCB circuit forming corrosion solution is increased by 200% to improve productivity, and the wastewater amount is reduced to 1/2, which is environmentally friendly, and can reproduce ultra-precision circuits, and there is no attack on the PCB circuit. Corrosive solutions have been required.

The present invention improves productivity by increasing the amount of copper dissolved in the corrosion etching solution for conventional PCB circuit formation by 200%, and reduces the amount of waste water by 1/2, which is environmentally friendly, and enables high-precision circuit reproduction and unlike PCBs. The purpose of the present invention is to provide a corrosion etching solution that does not penetrate into the solution, and to provide a method of automatically supplying a corrosion solution that can easily manage work and establish a database.

The present invention improves the disadvantages caused by copper corrosion of conventional corrosives and is intended for the formation of fine lines, micro-fine lines, inner layers and multi-layer high precision circuits. It provides high value-added corrosion etching working liquid and automatic etching liquid supplying method.

1 is a block diagram of the present invention automatic supply

※ Explanation of main code in drawing ※

1: NaClO ₃ tank 2: HCl tank 3, 3 ': Metering pump

4: circulation pump 5: etching chamber

The present invention relates to a method for supplying a regenerated composition and hydrochloric acid (HCl) as an oxidizing aid for the continuous operation of an etching solution, in particular, copper chloride-sodium chloride (CuCl ₂ -NaClO ₃₎ etching working solution for forming a PCB circuit,

Oxidizer per liter of regenerated composition is preferably 150-250 g / l sodium chloride (NaClO ₃ ), more preferably 170-230 g / l, 0.5-1.5 wt% of 1,2,3 benzotriazole, polytriazole and mixtures thereof Copper foil corrosion inhibitor, 1-3wt% peeling accelerator, 0.1wt% dilute alcohol alkoxylate, block copolymer system of ethylene oxide and propylene oxide, inhibitor, surfactant, 0.3wt% amine alone or as a mixture It is a regeneration composition which is composed of 40-60 g / l of additives and deionized water, and is a regeneration composition that regenerates the copper chloride-sodium chloride etching work solution mainly used for PCB circuit formation to enable continuous operation. At this time, as an oxidizing aid to be added at the same time, preferably, the ratio of regeneration composition 1: 35% hydrochloric acid is 1.3 to 1.5, and more preferably, the regeneration composition 1: 35% hydrochloric acid is 1.4.

The regenerated composition according to the invention is applied to industrial PCBs such as fine lines, fine pattern formation, micro-fine lines, ultra-precision circuit reproduction, inner layers and multi layers. The copper chloride-sodium chloride (CuCl ₂ -NaClO ₃ ) -based etching work solution can be regenerated and continuously etched, and the amount of copper dissolved higher than that of the conventional H ₂ O ₂ system, and the stability according to the low pH work conditions This is a reclaimed copper foil corrosion composition for forming PCB circuits with low cost, improved adhesion of dry film and edge separation.

Etching solution automatic supply of the present invention is SG: 1.3 ~ 1.5 (resolution: 0.02 or less)

It has a raw material and a characteristic of pH 1.3-1.5.

Etching liquid automatic feeder of the present invention is connected to a PC to manage the specific gravity, pH, absorbance, etc. of the etching work solution to automatically supply the regenerated composition and the oxidizing aid and measure the management items at 30 second intervals, the management items on the monitor screen It is possible to manage the etching work liquid more easily and accurately by displaying the chart, and it is possible to continuously work the etching work liquid used for panel corrosion as specific gravity, pH, and photo cell sensor control.

The comparison with other companies' products is as follows.

division Conventional device Conventional device The present invention How to measure Photocell ORP S.G + pH + Photocell + Temperature Advantages Easy to repair and replace Separate management of HCl, NaClO ₃ Easy work management, PC-enabled database construction, high-accuracy circuit reproduction with regeneration composition Disadvantages High drug consumption, difficult to control HCl concentration Difficult to manage Lack of Domestic Awareness Characteristic Replenishment of chemicals with increased photovoltaic cell (520 nm) HCl measures and supplies pH meter, NaClO ₃ measures and measures ORP meter Regenerate composition and HCl by specific gravity, assist HCl management by pH, and assist etching management with photocell

1.Replenishment solution to CuCl ₂ -NaClO ₃ etching work solution

Regenerated composition: supplement solution (oxidizer)

Appearance: Colorless transparent liquid

Specific gravity: 1.089 ~ 1.289 (1.189 ± 0.1)

pH: 6-8 (7 ± 1)

35% HCl: Supplement (oxidation aid)

2. Etching work condition

Specific gravity: 1.38 to 1.44 (1.41 ± 0.03)

pH: 1.3 to 1.5 (1.4 ± 0.1)

Cu concentration: 200 ~ 230g / ℓ (215 ± 15 g / ℓ)

Temperature: 50 to 54 ° C (52 ± 2 ° C)

3. How to bathe

a. Water is added to the etching machine, followed by rinsing by adding HCl 0.05% and circulating.

b. Drain the wash water in the chamber completely and replenish it to the liquid level with CuCl ₂ -NaClO ₃ etching solution.

c. After raising the temperature of CuCl ₂ -NaClO ₃ etching solution to 52 ℃, check specific gravity, pH and absorbance control device.

d. Work after the pH and specific gravity sensors are adjusted.

4. How to work

a. As the CuCl ₂ -NaClO ₃ etching solution proceeds to corrosion, the copper content increases and the specific gravity is high and the pH is low. If the specific gravity sensor is out of the specific gravity control range, the regeneration composition and hydrochloric acid are automatically replenished.

b. When the regeneration composition and hydrochloric acid are replenished so that the copper concentration does not exceed 250 g / l, the reworking solution is discharged before replenishment.

5. Management Items

a. importance

The copper concentration in the etching solution and the specific gravity of the etching solution are directly related to each other. As the work progresses, the copper concentration increases, which can be checked by the specific gravity sensor. The increase in specific gravity (Cu concentration) is caused by the increase of Cu ions, and the specific gravity must be controlled within the management range by supplementing the regeneration composition and hydrochloric acid.

b. pH

If the HCl concentration is out of the control range and the HCl concentration is high, chlorine dioxide and chlorine gas are generated, and if the HCl concentration is low, the oxidation reaction is completed and an addition reaction occurs in which copper hydroxide is precipitated. Therefore, the management of HCl is very important, and low concentration of HCl should be supplied with HCl periodically because the HCl deficiency easily occurs during the regeneration reaction. The replenishment of HCl by the autofiller should be managed to replenish HCl at pH 1.5 and stop replenishment at pH 1.2.

c. Absorbance

The change of the etching liquid can be managed by the absorbance sensor.

In the etching process, the regenerated composition is used as an oxidant of the reduced Cu + ions. If the regenerated composition is low, the oxidation reaction is delayed, and the color of the liquid is closer to greenish blue to black. Appropriate regeneration composition should be supplemented.

d. Temperature

Temperature controllers should be attached and heated and cooled to allow corrosion to proceed under appropriate temperature conditions (52 ° C).

e. Circulation of the working fluid

As the pH changes rapidly during the corrosive operation, the circulating pump must be large enough so that the replenishment can be mixed into the working solution as soon as possible (one cycle of working liquid volume should be carried out within 3 minutes).

f. Ventilation

Since chlorine dioxide and chlorine gas may be harmful to the human body during the corrosive operation, the corrode must be equipped with an adjustable exhaust system.

The method according to the invention has the following advantages.

(1) High density: The copper melt amount is very high, 230 to 240 g / l.

(2) HCl concentration is lower than that of H ₂ O ₂ system (pH 1.3 to 1.5)

(3) There is no risk of explosion.

(4) The price is cheaper than that of the H ₂ O ₂ system.

(5) There is no problem of dry film adhesion and edge area defect after development.

(6) The solution is stable and can be used as it is without replenishment even after standing for a long time.

(7) It is environmentally friendly due to high amount of copper dissolved and less waste liquid.

(8) Fine pattern etching is possible because of good etch factor.

Such evaluation items and evaluation method of the present invention

division Evaluation item Assessment Methods Application standard Performance Etching solution Etch factor Optical microscope 4.5 or more 4.5 or more 2.Cu concentration Wet analysis 220 to 240 g / l 230-240 g / ℓ 3. Uniformity Optical microscope Within 5㎛ Within 5㎛ 4.line width Optical microscope 100 μm 100 ± 3㎛ Automatic feeder 1. Sensor accuracy hydrometer 0.01 or less 0.01 or less 2. Sensor accuracy pH 0.05 or less 0.05 or less 3. Supply ratio Capacity ratio 1: 1.3 1: 1.3 4.absorbance Absorbance 520 nm 520 nm

Comparison of etching work solution which can be continuous work with the recycled composition of the present invention and the prior art

Item The present invention Conventional H ₂ O ₂ Etching Solution HCL concentration Low HCL concentration (pH 1.5 or below) (N concentration: 0.04 N or below) High HCL concentration (pH 0.5 or below) (N concentration: 2-3 N) Density Dissolution High density (~ 240 g / ℓ) (high copper dissolution) (high waste value compared to copper chloride) 1 ClO ₃ = 6Cu ⁺ → 6Cu ⁺⁺ Low density (~ 120 g / l) (low copper melt) 1 O ₂ = 2Cu ⁺ → 2Cu ⁺⁺ gassing Can be supplemented by strengthening the Cl ₂ + ClO ₂ gas generating band Low gas risk Solution stability The solution is stable and can be used as it is even if left for a long time After long-term storage, hydrogen peroxide turns into water and must be replenished with hydrogen peroxide. Risks No risk of explosion Explosive by hydrogen peroxide Circuit reproducibility Low HCl concentration prevents D / F adhesion problems and post-development edge separation Due to high HCl concentration, there may be a problem of adhesion of D / F and poor edge separation after development Coast Low price due to low HCl usage High price due to high amount of HCl

Etching Equipment Conditions of the Invention

Item division Ventilation necessary Cl ₂ + ClO ₂ gas generation risk cycle necessary Chamber 1 turn / 3min spray necessary 30 to 35 psi Burner, cooler necessary Coated steels such as quartz, teflon, prassol filter need Use of carbon filtration or common PP washable filters Auto Dosing need Automatic feeding by automatic feeding sensor Feed rate HCl 10 / min: Regenerated composition 4 / min

The chemical reaction of the present invention is as follows.

Cu ⁰ , CuCl ₂

Etching the copper foil (Cu ⁰⁾ is achieved by a CuCl ₂ etching of the work liquid (waste liquid).

Cu ⁺⁺ + Cu ⁰ → 2 Cu ⁺ (1)

The above reaction scheme is metallic copper (Cu ⁰⁾ by etching ClO ₃ working solution is simply shown to be a divalent copper (Cu ⁺⁺⁾ and reacting the reaction taking place at the substrate surface 1 a form a copper (Cu ^+).

2Cu⁺+ NaClO₃→ 2Cu⁺⁺(2)

In the above equation, one operation (Cu ⁺ ) reacted with NaClO ₃ in the regeneration composition during the spraying operation in the etching machine is oxidized to two operation (Cu ⁺⁺ ) again.

The reaction scheme is simplified and the reaction scheme of the ClO ₃ etching solution showing the importance of sodium chlorate, copper and chlorine is as follows.

Cu ⁰ + CuCl ₂ → ₂ CuCl (3)

6CuCl + NaClO₃+ 6HCl → 6CuCl₂ + 3H₂O + NaCl (4)

The copper component is supplied from the copper foil of the substrate, CuCl ₂ is contained in the etching working liquid (penetration) to corrode the circuit ((3) etching process), and sodium chlorate and chlorine are oxidized ((4) regeneration process) It is contained in the regeneration composition and hydrochloric acid to supplement.

Cu corrosion by the regenerated composition is carried out by repeating the steps (3) and (4).

Therefore, in order to obtain the best results, it is important for the operator to understand the relationship between specific gravity (Cu), pH (chlorine), and absorbance (Cu ions in the working solution) and to adjust the liquid composition most effectively.

The present invention will be described in more detail with reference to the accompanying drawings.

In FIG. 1, the etching composition is formed by pumping the regeneration composition tank 1 and the hydrochloric acid tank 2 through the pumps 3 and 3 'to the etching chamber 5, respectively.

The regenerated composition of the present invention is sodium chlorate (NaClO ₃ ) 170-230 g / l, 0.5-1.5 wt% 1,2,3 benzotriazole, polytriazole and mixture thereof, copper foil corrosion inhibitor, 1-3 wt% Accelerator, 0.1 wt% dilute alcohol alkoxylate or inhibitor of block coplymer system of ethylene oxide and propylene oxide. At this time, preferably, the regeneration composition 1: 35% hydrochloric acid 1.3 to 1.5, and more preferably the regeneration composition 1: 35% hydrochloric acid 1.4.

Regenerated Composition

Supplement division standard Regenerated Composition Furtherance (NaClO ₃ + additive + deionized water) Exterior Colorless transparent liquid importance 1.089 to 1.289 (1.189 ± 0.1) pH 6 to 8 (7 ± 1) 35% HCl ready to use

Etching Work Solution

Working fluid division Conditions of use Chamber Temperature 50 to 54 ° C (52 ± 2 ° C) Exterior Cyan Translucent Liquid importance 1.40 to 1.45 (1.425 ± 0.025) ORP 560 mv ～ 620mv (optimum 584 mv) Cu concentration 200 to 230 g / l (215 ± 15 g / l) pH 1.3 to 1.5 (1.4 ± 0.1)

Etching equipment condition

Item division Ventilation necessary Cl ₂ + ClO ₂ gas generation risk cycle necessary Chamber 1 turn / 3min spray necessary 30 to 35 psi Burner, cooler necessary Coated steels such as quartz, teflon, prassol filter need Use of carbon filtration or common PP washable filters Auto Dosing need Automatic feeding by automatic feeding sensor Feed rate HCl 10 / min: Regenerated composition 4 / min

The etching work solution is circulated by the circulation pump (4). The pH, specific gravity (SG), temperature (T), and absorbance (Abs) are measured to input data and compare the data to output the data to control the metering pump. Connect, monitor, record and continuously control data.

The temperature of deionized water is raised to 20 ° C. and added.

Regeneration composition 1: 35% hydrochloric acid 1.3 to 1.5 ratio, more preferably regeneration composition 1: 35% hydrochloric acid 1.4 ratio.

Analyze and control the process, filter the etched and inspect the packaged product.

The present invention improves productivity by increasing the amount of copper dissolved in the PCB circuit forming etching solution by 200%, and reduces the amount of waste water, which is eco-friendly and reproduces ultra-precision circuits. Computerized using PC as a composition, it provides an automatic supply device that can easily manage work and establish a database.

Claims (3)

It is a regeneration composition that regenerates sodium chlorate etching work solution to enable continuous work. A regeneration composition composed of 150-250 g / l sodium chlorate (NaClO ₃ ) as an oxidant per liter of regeneration composition, 40-60 g / l additive and deionized water. Oxidation aid to regenerate sodium chlorate etching work solution for continuous work. Regenerated composition 1: Supplying method with the ratio of 1.3-1.5 of 35% hydrochloric acid By connecting with PC, it manages etching density, pH, absorbance, etc. to automatically supply etching solution, measure management items every 30 seconds, and display management items on the monitor screen for easier and accurate etching solution management. Method of supplying etching solution for PCB circuit which enables continuous work of etching solution used for panel corrosion as specific gravity, pH, photo cell sensor control