KR100601490B1 - Method for recovering copper plating solution for filling up stacked via hole - Google Patents

Abstract

The present invention relates to a method for regenerating a stacked via-hole filled copper plating solution, which is an unnecessary aging component in a stacked via-hole filled copper plating liquid through photoreaction using a K ₄ Nb ₆ O ₁₇ photocatalyst having a selective removal performance against a brightener and ultraviolet light. It is characterized by treating with high selectivity.

According to the method of the present invention, it is possible to remove and selectively remove a gloss including a modified varnish, and exhibit a high gloss removal efficiency even under high dynamic concentrations, thereby controlling the filling performance of the stack type via hole according to the gloss modification. You can expect In addition, there is an advantage that the cost of bathing is reduced by extending the bathing cycle by optimizing the state of the entire copper plating solution.

Stack, Via Hole, Fill Copper Plating Solution, Regeneration, Photocatalyst, Ultraviolet

Description

Regeneration of Stacked Via Hole Filled Copper Powder {Method for recovering copper plating solution for filling up stacked via hole}

1 is a process flow diagram schematically showing a regeneration treatment method of a stacked via hole filled copper plating solution according to one embodiment of the present invention.

FIG. 2 is a process flowchart schematically illustrating a regeneration treatment method of a stacked via hole filled copper plating solution according to another embodiment of the present invention.

3 is a process flow diagram schematically showing a regeneration treatment method of a stacked via hole filled copper plating solution according to another embodiment of the present invention.

Figure 4 is a graph showing the removal efficiency of each organic additive of the copper plating solution recycled according to the method of Example 1 of the present invention.

5 is a graph showing contrast of removal efficiency for each organic additive of the copper plating solution regenerated by the method of Example 2 of the present invention.

6 is a graph showing the removal efficiency of each organic additive of the copper plating solution recycled according to the method of Example 3 of the present invention.

※ Explanation of symbols about main parts of drawing ※

10: liquid storage tank

20: photoreactor 21: low pressure mercury lamp

30: temperature control device 40: filtration device

The present invention relates to a regeneration treatment method of a stacked via hole filled copper plating solution. More specifically, the method for regenerating an efficient and productive stack type via hole filling plating solution capable of restoring a sufficient level of filling plating performance by selectively removing a gloss including modified varnish in an aging plating solution from a via filling plating tank of an HDI substrate. It is about.

In general, as the electroplating is performed after the dry bath, foreign substances such as substrates, dry films, and pretreatment liquids accumulate in the liquid and at the same time, when the organic compound introduced to improve the plating performance reacts with the anode ions, denaturation occurs to improve the plating performance. Will be degraded. In particular, unlike other substrates, the microvia of the HDI substrate has a relatively large hole diameter and depth, and thus the via filling performance is greatly affected by the aging degree of the liquid.

In this regard, the conventional aging plating solution processing method is largely divided into a method of decomposing or removing the old components, dummy electrolysis, UV / H ₂ O ₂ / O ₃ system.

First, the method of decomposing aging components is to use the fruit tree (H ₂ O ₂ ), which is an oxidizing agent, to decompose and change the gloss including the modified varnish into a material that does not affect the liquid performance relatively to improve the life and performance of the liquid. Way. The organic additives other than the brightener are not affected at this time. This method has the disadvantage of slow reaction processing. In addition, this method has a limitation in improving the life and performance of the liquid due to the decomposition of the inert material generated in the liquid as the treatment is repeated. Therefore, if you want to use for many months or more through the regeneration treatment of the plating solution, a treatment method through the removal of the aging material is required.

Second, the aging component can be removed by non-selective adsorption and removal of all organic matter in the liquid with activated carbon. The method of using powder or granular activated carbon or activated carbon cartridge physically adsorbs and removes all organic materials including aging components present in the plating solution. When using powder or granular activated carbon, the removal efficiency of organic matter is excellent, but activated carbon after treatment In the case of using activated carbon cartridges, the impurity caused by activated carbon is not generated in the plating liquid, whereas the removal efficiency of organic matter is low due to the small removal capacity, and the recovery of via filling is not sufficient.

Third, there is a method of dummy electrolysis using an insoluble anode and applying a high current. It is possible to process continuously or batchwise during the operation, but the copper concentration in the liquid decreases, so it is necessary to dissolve copper oxide, etc., and the amount of additives supplemented due to the reduction of all organic additives is disadvantageous.

In this regard, Korean Patent Laid-Open Publication No. 2002-93584 uses an electrolytic copper plating solution containing a specific sulfated compound, and dummy electrolysis of the electrolytic copper plating solution using an insoluble anode to electrolytically deposit copper on a substrate. An electrolytic copper plating method is introduced.

Fourth, there is a method in which fruit water is continuously or initially added to the liquid, and ozone is supplied to promote decomposition of the organic matter, and UV light is irradiated to oxidize. However, this method is not suitable for the stack type via hole plating solution because decomposition of the copper metal ion is not easy to occur.

For example, US Pat. No. 4,289,594 describes a process for reducing the concentration of copper ions and organic complexing agents dissolved in an electroless copper plating waste solution. The process chemically reduces copper ions to a copper metal at a concentration of less than 8 ppm in the first tank, then transports the solution to the second tank and then chemically precipitates the complexing agent. The solution is then contacted with ozone gas in the presence of ultraviolet (UV) to remove traces of organic additives remaining in the plating bath, and then the remaining liquid material is transferred to a general facility waste treatment system for processing. The invention requires reducing copper to less than 8 ppm to reduce the time required for the ozone oxidation process.

Also disclosed in US Pat. Nos. 4,849,114 and 4,792,407 are methods for oxidizing and reducing concentrations of toxic organic compounds in copper-free water using hydrogen peroxide in combination with ozone and UV. U. S. Patent 5,562, 822 describes a method for generating hydroxyl radicals in a fluid using ultraviolet and ozone gas and removing impurities from the waste fluid stream using the generated hydroxyl radicals.

In addition, Korean Patent Laid-Open Publication No. 2003-7692 describes systems and methods for selectively removing one or more organics and preferably one or more inorganic impurities from a plating bath. More specifically, the process uses an energy source with a chemical oxidant alone or with a catalyst to oxidize organic impurities in the plating bath to a level where the electroplating bath can be recovered and reused after appropriate chemical control. Here, the oxidative treatment method may be a continuous process or a batch process performed in a single pass and the end point of the oxidative process is detected by the sensor. In addition, residual organic matter and chlorine ions in the plating bath are removed from the solution by chemisorption or physical adsorption treatment. Inorganic impurities are removed from the electroplating bath by selective ion exchange resins or electrodialysis, and particulates and suspended colloidal particles are removed by filtration before the treated plating bath is recycled.

The conventional main copper liquid regeneration treatment method as described above is summarized in Table 1 below.

Aging solution composition treatment method Advantages Disadvantages Decomposition H ₂ O ₂ Simple process Slow processing speed, accumulation of decomposition products in liquid Activated carbon Powder, granular High efficiency (complete removal) Complex treatment, residual fine activated carbon Removal method cartridge Simple treatment, no residual activated carbon Efficiency Dummy Insoluble anode Efficiency The copper concentration in the plating liquid is reduced UV H ₂ O ₂ / O ₃ Efficiency If copper concentration is high, efficiency decreases rapidly

As described above, there have been efforts to improve the life and performance of the liquid by treating the aging component by the decomposition method of the aging component using an oxidizing agent, the dummy electrolysis method, and the adsorption removal method using the activated carbon. Was insignificant.

In particular, unlike ordinary copper plating solution, in the case of a copper plating solution for filling a stacked via hole, the filling performance is easily deteriorated due to the modification of the brightener, and due to the high copper concentration, conventional UV / H ₂ O ₂ / O ₃ treatment methods In addition to low treatment efficiency, the conventional treatment method has a disadvantage in that a high cost is required by removing all the organic additives at once.

Therefore, there is an urgent need to develop a recyclable treatment method for stack-type via hole filling copper plating solution that is equivalent to the via filling performance during initial bathing through an efficient and economical process.

Therefore, in the present invention, as a result of extensive research in order to solve the problems of the prior art as described above, stack-type via-hole filling plating through a K ₄ Nb ₆ O ₁₇ photocatalyst having a selective removal ability to the polishing agent and the photoreaction using ultraviolet light It has been found that unnecessary aging components in the waste liquid can be treated with high selectivity, and the present invention has been completed based on this.

Accordingly, it is an object of the present invention to provide a method for regenerating a stacked via-hole-filled copper plating solution capable of relatively selectively removing a gloss including a modified varnish.

Another object of the present invention is to provide a method for regenerating a stacked via-hole-filled copper plating liquid which exhibits high gloss removal efficiency even under high copper concentration.

It is still another object of the present invention to provide a method for regenerating a stacked via-hole filled copper plating solution in which the filling performance can be restored to the level equivalent to the via filling performance in the initial dry bath through an efficient and economical regeneration process.

Recycling treatment method of the stacked via hole filled copper plating solution according to the present invention for achieving the above and other objects are:

Stacked via hole-filled copper plating waste solution containing copper ions, organic additives and a brightening agent or a diluted solution thereof is irradiated with ultraviolet light in the presence of a K ₄ Nb ₆ O ₁₇ photocatalyst to selectively remove the brightening agent.

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

As described above, the conventional copper plating waste treatment and regeneration methods are for plating liquids containing low concentrations of copper, and the general copper plating liquids can be easily controlled. In the case of the general copper plating liquid, the aging of the liquid is caused by the accumulation of impurities in the liquid according to the long-term use, and the conventional method has focused on the treatment method for the impurities accumulated by the long-term use of the plating liquid. Therefore, in the case of using the existing method, not only the modified gloss that needs to be removed, but also other organic additives are removed more and more, accompanied by the removal of unnecessary parts, resulting in high cost and insufficient removal of the modified gloss. there was.

For example, in the case of using the existing UV / H ₂ O ₂ / O ₃ system, it is impossible to selectively remove the gloss including the modified varnish, so that the entire organic additive is removed. There was a low disadvantage.

In the present invention, in order to improve the problem of deterioration of filling performance due to denaturation of the varnish in a short time in the via-filling copper plating solution, which requires more sophisticated control, unlike the general copper plating solution, removal of the varnish component including the modified varnish compared to other organic additives By applying a regeneration system with higher selectivity to the reclaiming process, copper plating waste is regenerated through an efficient and productive process.

According to the present invention, a stacked via hole filled copper plating waste solution or a diluent thereof is regenerated, and the copper plating waste solution contains copper ions, an aqueous sulfuric acid solution and hydrochloric acid or NaCl, a brightener, a nonionic surfactant (Suppresser: PEG, PPG), Ionic surfactants (Levellers: thiourea, amines, polyamides, Dyes (Janus Green, Methyl Violet), quantized nitrogen compounds (-NH ₃ ⁺ )), wetting agents, brightening agents, organic acids such as phosphoric acid and sulfonic acids, and complexing agents Various organic additives, such as these, are contained.

Particularly, the gloss agent contained in the filled copper plating waste liquid is a component that acts as an accelerator of the plating process together with imparting gloss, and its content is about 0.1 to 3.0 mg / L, preferably about 0.5 to 1.5 mg / L, It is not specifically limited to this. The brightening agent is generally a mercapto compound (R-SH), disulfide compound (RSSR), dithio compound (R, R-CS-SR), dithiocarbamate compound (RO-CS-SR), thiouronium Sulfur compounds, such as compounds (R- [C = NH ₂ ⁺ ] -SR), denatured during plating and act as a major factor in degrading charging performance.

Therefore, in the present invention, other organic additives useful through photoreaction with K ₄ Nb ₆ O ₁₇ photocatalyst having selective removal performance with respect to the brightener component and ultraviolet rays remain and remove only the brightener component including the modified polish agent with high selectivity.

The K ₄ Nb ₆ O ₁₇ compounds Recently in the reaction for decomposing the water in the study generate oxygen and hydrogen, as a photocatalyst of the layered structure is found to be a very good activity than TiO₂ semiconductor photocatalyst, conventional oxide semiconductor (TiO _2, SrTiO ₃ ) photocatalysts have a different activity from the photocatalysts, and when a hole consuming agent such as methanol is added, hydrogen generation rate is very high.

When the Ni (NO ₃ ) ₂ precursor is supported on the K ₄ Nb ₆ O ₁₇ having the ion-exchange layered structure and subjected to oxidation and reduction treatment, about 5 kV of Ni is introduced into the upper layer of the K ₄ Nb ₆ O ₁₇ photocatalyst, and the lower layer is Forms a structure in which Ni is not introduced. Here, when UV light is irradiated to the K ₄ Nb ₆ O ₁₇ photocatalyst, the photocatalyst absorbs the UV light to generate e ⁻ and h ⁺ , and then decomposes water in two layers having different properties. Hydrogen is generated by the reaction of e ^- with water, which is transferred to Ni, and oxygen is generated by reaction of water with h ⁺ in the B layer. As such, the K ₄ Nb ₆ O ₁₇ photocatalyst generates a redox reaction between active sites, that is, interlayers, which is different from the conventional hydrolysis oxide photocatalysts.

In the present invention, when using the K ₄ Nb ₆ O ₁₇ photocatalyst as described above, it was found that the high selectivity is expressed especially in the removal of the brightener component compared to other organic additives and introduced into the copper plating waste regeneration system.

Meanwhile, a low pressure mercury lamp in which ozone is naturally generated without requiring an ozone supply process using an ozone generator as an ultraviolet light source used for ultraviolet irradiation in the photoreaction is preferable.

In general, when a photocatalyst such as TiO ₂ is used, a high-pressure mercury lamp having a high power of several kW is required in addition to low selectivity to the brightener component and also in the use of an ultraviolet light source, but according to the present invention, K ₄ Nb ₆ O _In the case of using a photocatalyst, a low power mercury lamp of several hundred watts can be used, which is advantageous in terms of efficiency and economy.

On the other hand, the photoreaction using the K ₄ Nb ₆ O ₁₇ photocatalyst and low-pressure mercury lamp in the present invention is not particularly limited and can be carried out in various forms as known in the art, particularly preferred embodiments thereof The explanation is as follows.

In this regard, the process of regeneration of the stacked via hole filled copper plating solution according to some preferred embodiments of the present invention is schematically illustrated in FIGS.

According to one embodiment of the present invention (see FIG. 1), the K ₄ Nb ₆ O ₁₇ photocatalyst is added to the filled copper plating waste liquid or its diluent in the liquid storage tank 10 under agitation in powder form, and then through a variable speed pump. The photoreaction is performed by ultraviolet rays supplied and circulated to the photoreactor 20 equipped with the low pressure mercury lamp 21 at the rear stage and irradiated from the low pressure mercury lamp 21.

Herein, the content of the K ₄ Nb ₆ O ₁₇ photocatalyst introduced into the packed copper plating waste solution or the diluent thereof is about 1000 to 1500 mg / L. When the content of the photocatalyst is less than 1000 mg / L, the active point causing the decomposition reaction is low, and the efficiency is low. When the photocatalyst is more than 1500 mg / L, the effective reaction active point does not increase because ultraviolet light is not irradiated on the surface throughout the photocatalyst. Rather it reduces efficiency.

In addition, it is preferable to maintain the temperature of the photoreactor to about 60 ~ 80 ℃ through the temperature control device 30 so that the brightener component can be sufficiently removed through the photoreaction, the wavelength of the radiation irradiated from the low pressure mercury lamp It is preferable that the range is 150-350 nm.

On the other hand, after the photoreaction, the photocatalyst powder present in the reclaimed copper plating solution can be filtered and reused through the filtration device 40.

According to another embodiment of the present invention (see FIG. 2), the K ₄ Nb ₆ O ₁₇ photocatalyst is fixed to the inner wall of the photoreactor 20 equipped with the low pressure mercury lamp 21 using a binder, and the liquid storage The filling copper plating waste liquid or the diluent thereof contained in the tank 10 is supplied and circulated through the speed variable pump to the photoreactor 20 at the rear stage, and the photoreaction is performed by ultraviolet rays irradiated from the low pressure mercury lamp 21.

Herein, the content of the K ₄ Nb ₆ O ₁₇ photocatalyst fixed to the inner wall of the photoreactor 20 is about 50-100 mg / cm 3. When the content of the photocatalyst is less than 50 mg / cm 3, the effective area in contact with the reactants is low in order to cause a decomposition reaction, and the efficiency is low when the photocatalyst exceeds 100 mg / cm 3. As it is limited, the efficiency does not increase any more and only the cost of using the catalyst increases.

In addition, it is preferable to maintain the temperature of the photoreactor to about 60 ~ 80 ℃ through the temperature control device 30 so that the brightener component can be sufficiently removed through the photoreaction, the wavelength of the radiation irradiated from the low pressure mercury lamp It is preferable that the range is 150-350 nm.

According to another embodiment of the present invention, the above-described selective removal method of the brightener through the photoreaction of the present invention is carried out at high efficiency even under high concentration, but in order to further improve the removal rate of the polisher to more efficiently recycle, As shown in FIG. 3, as a pretreatment process for lowering the copper concentration in the plating waste liquid before the photoreaction, a dummy using an insoluble anode and a cathode in the liquid storage tank 10 containing the stacked via hole filled plating waste liquid or its dilution liquid ) Electrolysis can be further performed.

In this case, the surface area ratio of the insoluble anode and the cathode is preferably 1: 2 to 5 in terms of efficiency and economy.

Meanwhile, the dummy electrolysis process may be selectively applied as a pretreatment process in all the copper plating regeneration treatment methods of the present invention, but in order to obtain a more maximized pretreatment effect, the photoreaction is relatively low in FIG. It is good to apply to the copper plating regeneration treatment method).

Hereinafter, the present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited thereto.

Example

The preparation method of K ₄ Nb ₆ O ₁₇ photocatalyst used in the experiment is as follows. The vessel mixed with K ₂ CO ₃ and Nb ₂ O ₅ in a stoichiometric ratio was put in a ball grinder and operated for 24 hours or longer, and then heated up at a rate of 10 ° C. to 1300 ° C. and maintained for 10 hours. Then by quenching to room temperature to obtain a layered structure of the K ₄ Nb ₆ O _17.

250 g / L of lactic acid copper, 30 g / L of sulfuric acid, 50 mg / L of chlorine ion were dissolved in pure water, and then 450 mg / L of polyethylene glycol as a nonionic surfactant, 10 mg / L of pidolic acid as an ionic surfactant, and bis (as a brightening agent). 1.0 mg / L of 3-sulfopropyl) disulfide disodium and 0.5 mg / L of 3-mercapto-1-propanesulfonate sodium salt were added as a modified varnish of the above-mentioned gloss, and 30 L of an electroplating solution was prepared and used in the experiment. Before and after the treatment of the plating solution, the CVS analyzer and the haring cell plating result used the via hole dimple size measurement. Harling cell plating was performed after replenishing the concentrations of the nonionic surfactant and the ionic surfactant consumed before the plating, and replenishing the varnish so that the total of the varnish and the modified varnish was 1.5 mg / L.

The temperature of the liquid in the reactor was adjusted to 60 to 80 ° C. using a temperature controller.

Example 1

In Figure 1, 30 g of K ₄ Nb ₆ O ₁₇ powder prepared at the beginning of the reaction are placed in a liquid storage tank and stirred evenly. A variable speed pump was operated in a reactor equipped with four low pressure mercury lamps for 150W ozone generation to supply copper liquid from the liquid storage tank. After completion of the reaction, the powder photocatalyst was filtered through a filtration filter, and then a plating solution was used for plating a haring cell.

As a result of the experiment, the concentration reduction rate for each organic additive according to the reaction time is shown in FIG. 4. It can be seen from the result that the removal of the polishing agent occurs faster than other organic additives, the polishing agent is removed with a relative selection advantage. In addition, before and after the reaction, the Haringel plating showed a via hole dimple size. It can be seen that the filling performance of the via hole was restored by the removal of the modified varnish.

Example 2

In FIG. 2, about 50 mg / cm 3 of K ₄ Nb ₆ O ₁₇ was fixed to the inner wall of the reactor equipped with four 150W low-pressure mercury lamps for ozone generation. The variable speed pump was operated to supply the plating liquid from the liquid storage tank to the reactor.

As a result of the experiment, the concentration reduction rate for each organic additive according to the reaction time is shown in FIG. 5. It can be seen from the result that the removal of the polishing agent occurs faster than other organic additives, the polishing agent is removed with a relative selection advantage. In addition, before and after the reaction, the Haringel plating showed a via hole dimple size. It can be seen that the filling performance of the via hole was restored by the removal of the modified varnish. Compared to the photocatalyst in powder form, the removal efficiency is relatively low, but the separation process is not required.

Example 3

Before starting the photoreaction in Figure 3 was first carried out for 10 hours to reduce the copper concentration to increase the photoreaction rate and to remove the organic additives. Here, electroplating was performed by applying a current of ² A / dm ^{2 using} a platinum coated titanium as an anode and a substrate having an area three times the area of the anode as a cathode. The copper concentration and the concentration change of the organic additive according to the reaction time are shown in FIG. 6. Thereafter, photoreaction was performed through the procedure used in Example 2.

As a result of the experiment, the concentration decrease rate was shown for each organic additive according to the reaction time. The degree of removal of the brightening agent can be seen that occurs faster than the case of Example 2 with a high copper concentration. In addition, the size of the via hole dimple before and after the reaction showed that the filling performance of the via hole was restored to the level of the bathing time due to the sufficient removal of the modified varnish. However, there is a disadvantage in that copper oxide must be dissolved and added to compensate for the reduced copper concentration after the removal reaction.

As described above, according to the regeneration treatment method of the stacked via hole filled copper plating solution of the present invention, it is possible to effectively control the stacked via hole filling performance according to the modification of the brightener to expect a sufficient level of filling plating performance, and the state of the entire copper plating solution. The cost of bathing can be reduced by extending the bathing cycle by optimizing it.                     

In addition, it is possible to reduce the cost by minimizing the unnecessary removal of other additives by the relative selective removal of the varnish including the modified varnish, and to efficiently remove the modified varnish without non-ideally lowering the high copper concentration. In addition, by using a low pressure mercury lamp that generates ozone without the need for ozone supply using a separate ozone generator, there is an advantage that the copper plating waste liquid can be regenerated through an efficient and economical process.

Claims (13)

Stacked via hole filled copper plating waste solution containing copper ions, organic additives, and brighteners or diluting liquids thereof are irradiated with UV light in the presence of a K ₄ Nb ₆ O ₁₇ photocatalyst to selectively remove the brightening agent. Regeneration treatment method of the filled copper liquid. The method of claim 1, wherein the source of ultraviolet rays is a low pressure mercury lamp for ozone generation. The method of claim 1, wherein the polishing agent is selected from the group consisting of mercapto compound, disulfide compound, dithio compound, dithio carbamate compound and thiouronium compound regeneration treatment of the stacked via hole filled copper plating solution Way. The photocatalyst according to claim 1 or 2, wherein the K ₄ Nb ₆ O ₁₇ photocatalyst is added in powder form to the stacked via hole filled copper plating waste solution or diluent thereof in the liquid storage tank, and then supplied to the photoreactor equipped with a low pressure mercury lamp. And recycling the stacked via-hole filled copper plating solution. 5. The method of claim 4, wherein the content of the K ₄ Nb ₆ O ₁₇ photocatalyst in the stacked via-hole filled copper plating waste solution or the diluent thereof is 1000 to 1500 mg / L. The method of claim 4, wherein the temperature of the photoreactor is 60 ° C. to 80 ° C. 6. The method of claim 4, wherein the K ₄ Nb ₆ O ₁₇ photocatalyst powder is filtered and reused after completion of the photoreaction. The photocatalyst of claim 1 or 2, wherein the K ₄ Nb ₆ O ₁₇ photocatalyst is fixed to the inner wall of the photoreactor equipped with the low pressure mercury lamp through a binder, and the stacked via hole filled copper plating waste liquid in the liquid storage tank or diluent thereof is And the photocatalyst is fed and circulated to the fixed photoreactor. 10. The method of claim 8, wherein the content of the K ₄ Nb ₆ O ₁₇ photocatalyst fixed to the inner wall of the photoreactor is 50 to 100 mg / cm 3. The method of claim 8, wherein the temperature of the photoreactor is 60 to 80 ° C. 10. The method of claim 1, wherein the method is a pretreatment step for lowering the copper concentration of the stacked via hole filled copper plating waste liquid, and the stacked via hole filled copper plating waste liquid or its diluted solution is subjected to dummy electrolysis using an insoluble anode and a cathode before the photoreaction. A method of regenerating a stacked via hole-filled copper plating solution further comprising the step of electrolysis. 12. The method of claim 11, wherein the ratio of the surface area of the insoluble anode and the cathode is 1: 2 to 5. The method of claim 2, wherein the low-pressure mercury lamp radiation ranges from 150 nm to 350 nm.

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