CN117684173A - Copper surface leveling agent, copper surface leveling working fluid and copper surface leveling method - Google Patents

Abstract

The application provides a copper surface flattening agent, a copper surface flattening working solution and a copper surface flattening method, wherein the copper surface flattening agent comprises 0.1-0.7 part of dipicolinic acid, 1-5 parts of hydroxycarboxylic acid and 4-7 parts of deionized water; the copper surface flattening agent containing the pyridine dicarboxylic acid and the hydroxycarboxylic acid is used, in the process of processing the smoothness of the copper surface, bivalent copper reacts with single copper to generate monovalent copper, the monovalent copper is generated more easily at the crest of the copper surface because the copper surface is roughness, and further the crest of the copper surface is prevented from generating corrosion reaction, the pyridine dicarboxylic acid is used as a complexing agent, and the monovalent copper can be complexed in time, so that the simple substance copper at the crest of the copper surface is easier to further react, the hydroxycarboxylic acid is used as a corrosion inhibitor, the reaction speed at the trough of the copper surface is reduced, under the synergistic effect of the pyridine dicarboxylic acid and the hydroxycarboxylic acid, the reaction at the crest of the copper surface is relatively fast, and the reaction at the trough of the copper surface is relatively slow, so that the roughness is reduced, and meanwhile, the hydroxycarboxylic acid is used as an inhibitor to reduce the corrosion amount of copper atoms.

Description

Copper surface leveling agent, copper surface leveling working fluid and copper surface leveling method

Technical field

The present invention relates to the technical field of IC packaging substrate manufacturing processes, and specifically to a copper surface leveling agent, a copper surface leveling working fluid and a copper surface leveling method.

Background technique

In the production and manufacturing of printed circuit boards, IC carrier boards and other products, in order to etch the required circuits on the copper foil, it is necessary to first attach a layer of dry film to the copper foil, and then expose the circuit pattern through exposure and development. , and then etching away the unnecessary areas through chemical etching, thus forming the required circuit pattern. This process requires sufficient adhesion between the dry film and the copper foil to ensure product quality and yield. Surface roughening is a commonly used treatment method to improve adhesion, that is, by increasing the specific surface area of the conductor copper to increase the contact area between the conductor copper and the dry film, thereby forming a long-lasting and stable adhesion. Commonly used roughening pre-treatments include Grinding, sandblasting, chemical roughening and other methods, among which chemical roughening is widely used because of its good roughening effect, easy use and maintenance. Therefore, after the circuit process is completed, the copper surface roughness of the circuit pattern formed is relatively Large. When bonding IC carrier boards, especially BT carrier boards, there are high requirements for the flatness of the nickel-gold surface on the bonding surface, and nickel-gold is deposited on the surface of copper, so the copper surface is smooth. Degree has become a key factor. Based on the above situation, before the final surface treatment (nickel-gold) of the product, a copper surface smoothing process is required. The rough copper surface is chemically smoothed to a certain smoothness to meet the requirements of future bonding. Set requirements.

In the existing technology, the copper surface planarization process adopts the ordinary copper surface micro-etching process, that is, the sulfuric acid hydrogen peroxide system and the sulfuric persulfuric acid system are used to micro-etch the copper surface to reduce the roughness of the copper surface. The roughness treatment effect is poor. And the corrosion of copper is relatively large.

Contents of the invention

In view of the shortcomings of the existing technology, this application provides a copper surface leveling agent, a copper surface leveling working fluid and a copper surface leveling method.

An additive for copper surface smoothing disclosed in this application includes 0.1-0.7 parts of picolinedicarboxylic acid, 1-5 parts of hydroxycarboxylic acid and 4-7 parts of deionized water.

Preferably, the pyridinedicarboxylic acid is any one or both of 3,5-pyridinedicarboxylic acid and 2,6-pyridinedicarboxylic acid.

Preferably, the hydroxycarboxylic acid is any one or more of 2-hydroxysuccinic acid, 2-hydroxypropionic acid, and β-hydroxybutyric acid.

Preferably, the amount of picolinedicarboxylic acid is 0.3-0.5 parts.

Preferably, the hydroxycarboxylic acid is 2-4 parts.

Preferably, the copper surface smoothing agent also includes 0.8-2.1 parts of stabilizer.

Preferably, the stabilizer includes 0.1-0.5 parts of potassium citrate and 0.7-1.6 parts of potassium sulfate.

According to the second aspect of the present invention, this application provides a copper surface smoothing agent.

A copper surface smoothing agent disclosed in this application includes sulfuric acid 52.25-57.75g/l, potassium hydrogen persulfate 76-84g/l, copper surface smoothing agent 190-210ml/l and the balance plasma water.

According to the third aspect of the present invention, the present application provides a copper surface leveling method.

The application of a copper surface leveling agent disclosed in this application is characterized in that, before the IC carrier board is converted into nickel and gold, a copper surface smoothing working fluid is used to smooth the roughened copper surface of the IC carrier board.

The beneficial effects of this application are: using a copper surface smoothing additive containing picolinic acid and hydroxycarboxylic acid, in the process of processing the copper surface smoothing finish, divalent copper will react with elemental copper to form monovalent copper. Since copper The surface is rough, and monovalent copper is more likely to be generated at the wave peak, thereby preventing the corrosion reaction at the wave peak of the copper surface. As a complexing agent, pyridinedicarboxylic acid can complex away the monovalent copper in time, so that the elemental substance at the wave peak is Copper is more likely to react further, which means that the elemental copper in the convex part is more likely to react further. The presence of hydroxycarboxylic acid as a corrosion inhibitor reduces the reaction speed at the trough. Under the synergistic effect of the two, the reaction at the crest is relatively fast. , the reaction at the trough is relatively slow, thereby reducing the roughness. At the same time, the hydroxycarboxylic acid acts as an inhibitor to reduce the amount of corrosion of elemental copper, allowing the copper surface to achieve a better copper surface smoothness with a small amount of corrosion. Smooth finish effect.

Detailed ways

Multiple embodiments of the present application will be disclosed in the following drawings. For the sake of clarity, many practical details will be explained in the following description. However, it is understood that these practical details shall not limit the application. That is to say, in some implementations of the present application, these practical details are not necessary. In addition, in order to simplify the drawings, some commonly used structures and components will be shown in the drawings in a simple schematic manner.

The technical solutions in various embodiments can be combined with each other, but it must be based on the realization by those of ordinary skill in the art. When the combination of technical solutions is contradictory or cannot be realized, it should be considered that such combination of technical solutions does not exist, and It is not within the scope of protection required by this application.

In order to further understand the application content, features and functions of this application, the following examples are given and described in detail with the accompanying drawings.

Embodiment 1

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.4 parts of 3,5-pyridinedicarboxylic acid, 3 parts of 2-hydroxypropionic acid, 0.2 parts of potassium citrate, 1.0 parts of potassium sulfate and deionized water 5.4 parts. The above parts are all mass ratios. For example, the mass ratio of 3,5-pyridinedicarboxylic acid and 2-hydroxypropionic acid is 0.4:3.

The copper surface smoothing working fluid in the present invention is based on oxidizing substances such as sodium persulfate, potassium hydrogen persulfate, and hydrogen peroxide. Under acidic conditions, the roughened IC carrier board, especially the BT carrier board, is subjected to copper surface treatment. Surface smoothing treatment to meet the flatness of the nickel and gold surfaces of the bonded surface of the IC carrier board. Different oxide systems use different additives for copper surface smoothing. The present invention is a copper surface smoothing suitable for the potassium hydrogen persulfate system. Use additives.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Before the IC substrate is converted into nickel gold, the above-mentioned copper surface leveling working fluid is used to level the roughened copper surface of the IC substrate. During the reaction process, potassium hydrogen persulfate reacts with the copper elemental substance, oxidizing the copper from the elemental form to Divalent copper ions, and divalent copper ions react with elemental copper to generate monovalent copper ions under this condition. Since the copper surface is rough, monovalent copper ions are more likely to be generated at the wave peak. The presence of monovalent copper inhibits The oxidation reaction of elemental copper at the wave peak also inhibits the oxidation reaction of elemental copper at the bumps on the copper surface, which in turn affects the corrosion effect of the copper surface at the bumps, resulting in poor copper surface roughness leveling effect. Adding a copper surface leveling agent After adding the additive, pyridinedicarboxylic acid complexes away the monovalent copper ions in time, and the monovalent copper ions are reduced, which promotes the oxidation reaction of the copper element, making it easier for the copper element at the wave peak to react. The presence of hydroxycarboxylic acid as a corrosion inhibitor reduces the The reaction speed at the trough is reduced, that is, the reaction speed of the copper element in the depression is reduced. Under the synergistic effect of picolinic acid and hydroxycarboxylic acid, the reaction at the crest of the copper surface is relatively fast, and the reaction at the trough of the copper surface is relatively slow. In turn, the copper surface is relatively smooth, and the hydroxycarboxylic acid also acts as an inhibitor to inhibit the corrosion of copper by oxidants.

Potassium citrate and potassium sulfate serve as stabilizers to reduce the decomposition of persulfate aqueous solution and increase the service life of the working fluid.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Embodiment 2

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.4 parts of 3,5-pyridinedicarboxylic acid, 3 parts of 2-hydroxypropionic acid, and 5.4 parts of deionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Embodiment 3

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.4 parts by weight of 2,6-pyridinedicarboxylic acid, 3 parts by 2-hydroxysuccinic acid, 0.2 parts by potassium citrate, and 1.0 parts by potassium sulfate, deionized 5.4 parts of water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the working fluid prepared above to test the roughness of the copper surface.

Embodiment 4

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.3 parts of 3,5-pyridinedicarboxylic acid, 0.4 parts of 2,6-pyridinedicarboxylic acid, 3 parts of 2-hydroxysuccinic acid, potassium citrate 0.2 parts, potassium sulfate 1.0 parts, deionized water 5.4 parts.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 190ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Embodiment 5

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.1 part of 3,5-pyridinedicarboxylic acid, 1 part of β-hydroxybutyric acid, 0.1 part of potassium citrate, 0.7 part of potassium sulfate, deionized water 5.4 servings.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 210ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Embodiment 6

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.4 parts by weight of 2,6-pyridinedicarboxylic acid, 5 parts by 2-hydroxypropionic acid, 0.5 parts by potassium citrate, and 1.6 parts by potassium sulfate, deionized 7 parts water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Embodiment 7

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.2 parts of 3,5-pyridinedicarboxylic acid, 0.2 parts of 2,6-pyridinedicarboxylic acid, 2 parts of 2-hydroxysuccinic acid, β-hydroxyl 2 parts of butyric acid, 0.2 parts of potassium citrate, 1.0 parts of potassium sulfate, and 4 parts of deionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Comparative Example 1

Use the sodium persulfate system on the market to prepare the smoothing agent working fluid as follows:

Sulfuric acid: 55g/l, sodium persulfate: 90g/l, sodium persulfate stabilizing additive: 400ml/l, deionized water: balance.

Use the working fluid prepared above to test the roughness of the copper surface.

Comparative Example 2

Use the hydrogen peroxide system on the market to prepare the smoothing agent working fluid as follows:

The preparation of traditional microetchant working fluid is as follows:

Sulfuric acid: 55g/l, hydrogen peroxide: 30ml/l, hydrogen peroxide stabilizing additive: 30ml/l, deionized water: remainder.

Use the working fluid prepared above to test the roughness of the copper surface.

Comparative Example 3

Use the potassium hydrogen persulfate system on the market to prepare the smoothing agent working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, stabilizer: 200ml/l, deionized water: balance.

Comparative Example 4

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.2 parts by weight of 3,5-pyridinedicarboxylic acid, 0.2 parts by 2,6-pyridinedicarboxylic acid, 0.1 part by 2-hydroxysuccinic acid, and potassium citrate 0.2 parts, 1.0 parts potassium sulfate, 4 parts deionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Comparative Example 5

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 0.2 parts of 3,5-pyridinedicarboxylic acid, 0.2 parts of 2,6-pyridinedicarboxylic acid, 0.2 parts of potassium citrate, and 1.0 parts of potassium sulfate. 4 parts of ionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Comparative Example 6

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 1 part of 3,5-pyridinedicarboxylic acid, 1 part of 2,6-pyridinedicarboxylic acid, 1 part of 2-hydroxysuccinic acid, potassium citrate 0.2 parts, 1.0 parts potassium sulfate, 4 parts deionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Comparative Example 7

The copper surface smoothing agent in this example is prepared from the following raw materials by weight: 1 part of 2-hydroxysuccinic acid, 0.2 parts of potassium citrate, 0.2 parts of potassium citrate, 1.0 parts of potassium sulfate, and 4 parts of deionized water.

Use the above copper surface smoothing agent to prepare the copper surface smoothing working fluid as follows:

Sulfuric acid: 55g/l, potassium hydrogen persulfate: 80g/l, copper surface smoothing agent: 200ml/l, deionized water: remainder.

Use the copper surface smoothing working fluid prepared above to conduct a copper surface roughness test.

Performance Testing:

The IC carrier board after circuit etching is smoothed with the working fluid prepared in the above embodiments. The surface roughness test of the processed board is as follows:

According to the test of the above examples, compared with the existing technology, the roughness of the copper surface treated by the treatment liquid with additives for copper surface smoothing is significantly reduced.

In summary, when using copper surface smoothing additives containing picolinic acid and hydroxycarboxylic acid, during the process of processing the copper surface smoothing finish, divalent copper will react with elemental copper to form monovalent copper, because the copper surface is rough. Therefore, monovalent copper is more likely to be generated at the wave peak, thereby preventing the corrosion reaction at the wave peak on the copper surface. As a complexing agent, pyridinedicarboxylic acid can complex away the monovalent copper in time, making it easier for the elemental copper at the wave peak to further reaction, that is, the elemental copper in the convex part is more likely to react further. The presence of hydroxycarboxylic acid as a corrosion inhibitor reduces the reaction speed at the trough. Under the synergistic effect of the two, the reaction at the crest is relatively fast, and the reaction at the trough is relatively fast. It is relatively slow, thereby reducing the roughness. At the same time, the hydroxycarboxylic acid acts as an inhibitor to reduce the amount of corrosion of elemental copper, so that the copper surface can achieve a better smooth surface finish with a small amount of corrosion.

The above are only implementation modes of the present application and are not used to limit the present application. To those skilled in the art, various modifications and variations may be made to this application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this application shall be included in the scope of the claims of this application.

Claims (9)

1. A copper surface leveler, comprising: 0.1-0.7 parts of dipicolinic acid, 1-5 parts of hydroxycarboxylic acid and 4-7 parts of deionized water.

2. The copper surface leveling agent according to claim 1, wherein the dipicolinic acid is one or both of 3, 5-dipicolinic acid and 2, 6-dipicolinic acid.

3. The copper surface leveling agent according to claim 1, wherein the hydroxycarboxylic acid is any one or more of 2-hydroxysuccinic acid, 2-hydroxypropionic acid, and β -hydroxybutyric acid.

4. A copper surface leveler according to claims 1 to 3, wherein said dipicolinic acid is 0.3 to 0.5 parts.

5. A copper facing leveler according to claims 1-3, wherein said hydroxycarboxylic acid is 2-4 parts.

6. A copper facing leveler according to claims 1-3, wherein said copper facing leveler further comprises 0.8-2.1 parts of a stabilizer.

7. The copper leveler according to claim 6, wherein said stabilizer comprises 0.1 to 0.5 parts of potassium citrate and 0.7 to 1.6 parts of potassium sulfate.

8. A copper surface leveling working solution, which is characterized by comprising 52.25-57.75g/l of sulfuric acid, 76-84g/l of potassium hydrogen persulfate, 190-210ml/l of the copper surface leveling agent according to any one of claims 1-7 and the balance of deionized water.

9. A copper surface leveling method, which is characterized in that the copper surface after coarsening of an IC carrier is leveled by using the copper surface leveling working solution according to claim 8 before nickel-gold plating of the IC carrier.