US20230120741A1

US20230120741A1 - Electroplating apparatus and electroplating method

Info

Publication number: US20230120741A1
Application number: US17/700,531
Authority: US
Inventors: Heng-Ming Nien; Cho-Ying Wu; Shih-Lian Cheng
Original assignee: Unimicron Technology Corp
Current assignee: Unimicron Technology Corp
Priority date: 2021-10-14
Filing date: 2022-03-22
Publication date: 2023-04-20

Abstract

Provided is an electroplating apparatus including an electroplating tank, an anode and a cathode, a power supply, and a regulating plate. The electroplating tank accommodates electrolyte. Both the anode and the cathode are disposed in the electroplating tank. The power supply is electrically connected to the anode and the cathode. The regulating plate is disposed between the anode and the cathode. The regulating plate includes a plurality of mesh openings and a plurality of metal sheets, and at least part of the metal sheets is electrically connected with the cathode. An electroplating method is also provided.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the priority benefits of U.S. provisional application Ser. No. 63/255,438, filed on Oct. 14, 2021, and Taiwan application serial no. 111106298, filed on Feb. 22, 2022. The entirety of each of the above-mentioned patent applications is hereby incorporated by reference herein.

BACKGROUND

Technical Field

The disclosure relates to an apparatus and a method, particularly to an electroplating apparatus and an electroplating method.

Description of Related Art

Electroplating is a technique widely used in various fields. Besides being a surface treatment, electroplating is also applied in the production of circuit boards, semiconductor chips, LED conductive substrates, and semiconductor packages. Common and conventional as the technique is, electroplating still often has the issues of producing metal layers with non-uniform thickness.
One of the reasons is that, in the manufacturing process of circuit boards, the power lines between the anode and the cathode are often affected and steered by the upper layer (with, for example, insulation characteristics that affect the power distribution) when they are close to the to-be-plated substrate, which makes the distribution density of power line uneven. As a result, the metal layer formed on the to-be-plated substrate is troubled by poor uniformity in thickness.

SUMMARY

The disclosure provides an electroplating apparatus and an electroplating method that resolve the problem of poor electroplating thickness uniformity of a metal plating layer on a to-be-plated substrate.
An electroplating apparatus of the present disclosure includes an electroplating tank, an anode and a cathode, a power supply, and a regulating plate. The electroplating tank accommodates electrolyte. Both the anode and the cathode are disposed in the electroplating tank. The power supply is electrically connected to the anode and the cathode. The regulating plate is disposed between the anode and the cathode. The regulating plate includes multiple mesh openings and multiple metal sheets, and at least part of the metal sheets is electrically connected with the cathode.
In an embodiment of the disclosure, the mesh openings are part of an insulating mesh panel, the metal sheets are disposed on the insulating mesh panel, and the metal sheets are all electrically connected with the cathode.
In an embodiment of the disclosure, channels are only formed by the above-mentioned mesh openings.
In an embodiment of the disclosure, the electroplating apparatus further includes multiple wires connecting to the metal sheets one-to-one.
In an embodiment of the disclosure, the electroplating apparatus further includes a controller connected to the wires, wherein currents of the wires are collected to the cathode by the controller.
In an embodiment of the disclosure, the shape of the mesh openings re complementary to the shape of the metal sheets.
In an embodiment of the disclosure, the mesh openings are part of an insulating mesh panel, the metal sheets are disposed into arrays on the insulating mesh panel, part of the metal sheets is electrically connected to the cathode, and the other part of the metal sheets is not electrically connected to the cathode.
In an embodiment of the disclosure, each of the metal sheets includes at least one hole, and the holes and the mesh openings form channels.
In an embodiment of the disclosure, the electroplating apparatus further includes multiple wires connecting to the metal sheets one-to-one.
In an embodiment of the disclosure, the electroplating apparatus further includes a controller connected with the wires, where the controller is configured to control electrical connection states of the regulating plate.
An electroplating method of the disclosure at least includes the following steps. An electroplating apparatus is provided, and the electroplating apparatus includes an electroplating tank, an anode and a cathode, a power supply, and a regulation plate. The electroplating tank accommodates electrolyte. Both the anode and the cathode are disposed in the electroplating tank. The power supply is electrically connected to the anode and the cathode. The regulating plate is disposed between the anode and the cathode. The regulating plate includes multiple mesh openings and multiple metal sheets, and at least part of the metal sheets is electrically connected with the cathode. A to-be-plated substrate is fixed on the cathode. After the power supply supplies power, multiple power lines are formed between the anode and the cathode, and the power lines move from the anode to the cathode. A first metal plating layer is formed on the to-be-plated substrate, as part of the power lines drives part of the metal ions in the electrolyte to pass through the regulating plate. A second metal plating layer is formed on the regulating plate, as another part of the power lines drives another part of the metal ions in the electrolyte.
In an embodiment of the disclosure, the mesh openings are part of an insulating mesh panel, the metal sheets are disposed on the insulating mesh panel, and the metal sheets are all electrically connected with the cathode to form the second metal plating layer on all of the metal sheets.
In an embodiment of the disclosure, the shape of the mesh openings is complementary to the shape of the metal sheets.
In an embodiment of the disclosure, the electroplating apparatus further includes multiple wires connecting to the metal sheets one-to-one.
In an embodiment of the disclosure, the electroplating apparatus further includes a controller connected with the wires, and the currents of the wires are collected to the cathode by the controller.
In an embodiment of the disclosure, the to-be-plated substrate includes a dry film having multiple openings, and the mesh openings are aligned with the openings.
In an embodiment of the disclosure, the mesh openings are part of an insulating mesh panel, the metal sheets are disposed into arrays on the insulating mesh panel, and only part of the metal sheets is electrically connected to the cathode to form the second metal plating layer only on part of the metal sheets.
In an embodiment of the disclosure, each of the metal sheets includes at least one hole, and the holes of the metal sheets without the second metal plating layer form channels with the mesh openings.
In an embodiment of the disclosure, the electroplating apparatus further includes multiple wires electrically connected to the metal sheets one-to-one.
In an embodiment of the disclosure, the electroplating apparatus further includes a controller connected with the wires, and the controller is configured to control electrical connection states of the regulating plate.
Based on the above, with the design of a regulating plate between the anode and the cathode in the electroplating apparatus of the disclosure, part of the power lines moving from the anode to the cathode may drive part of the metal ions in the electrolyte to pass through the mesh openings of the regulating plate and form a metal plating layer on the to-be-plated substrate, whereas another part of the of power lines may drive another part of the metal ions in the electrolyte to form a metal plating layer on the metal sheets on the regulating plate. With this configuration, the power lines may be redistributed, and the part where circuits are formed on the to-be-plated substrate has a consistent density of the power lines, thereby resolving the problem of poor plating thickness uniformity of the metal plating layer on the to-be-plated substrate.
To make the above features and advantages of the disclosure to be understood easily, the following embodiments are described in detail with reference to the following drawings.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1A is a flowchart of an electroplating method according to an embodiment of the disclosure.

FIG. 1B is a schematic side view of an electroplating apparatus according to an embodiment of the disclosure.

FIG. 1C is a schematic top view of a regulating plate of an electroplating apparatus according to an embodiment of the disclosure.

FIG. 1D is a schematic top view of a regulating plate according to another embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

Explanatory embodiments of the disclosure are described below with reference to the drawings. As the disclosure may also be embodied in many different forms, the embodiments described herein should not be construed as a limitation to the disclosure. For the sake of clarity, the size and thickness of various regions, parts, and layers may not be drawn to scale in the drawings. For the ease of comprehension, the same or similar elements adopt the same reference numerals in the following description, and the same descriptions are not repeated in the paragraphs to come.
Directional terms (e.g., up, down, right, left, front, back, top, bottom) used herein are only for reference shown in the drawings and are not intended to imply absolute orientation.
Although the terms “first,” “second,” “third,” etc. may be used herein to describe various elements, components, regions, layers, and/or sections, these elements, components, regions, and/or or parts shall not be limited by these terms. These terms are only used to distinguish one element, component, region, layer, or section from another element, component, region, layer, or section.
Unless defined otherwise, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art.
FIG. 1A is a flowchart of an electroplating method according to an embodiment of the disclosure. FIG. 1B is a schematic side view of an electroplating apparatus according to an embodiment of the disclosure. FIG. 1C is a schematic top view of a regulating plate of an electroplating apparatus according to an embodiment of the disclosure. FIG. 1D is a schematic top view of a regulating plate according to another embodiment of the disclosure.
Please refer to FIG. 1A, FIG. 1B, and FIG. 1C. The following passages describe the main flow of the electroplating method according to an embodiment of the disclosure with reference to the drawings. First, an electroplating apparatus 100 is provided, and the electroplating apparatus 100 includes an electroplating tank 110, an anode 120 and a cathode 130, a power supply 140, and a regulating plate 150 (step S100). The electroplating tank 110 accommodates electrolyte 112. Both the anode 120 and the cathode 130 are disposed in the electroplating tank 110, and the power supply 140 is electrically connected to the anode 120 and the cathode 130. The regulating plate 150 is disposed between the anode 120 and the cathode 130 (two anodes 120 respectively sandwich a regulating plate 150 with a cathode 130, as shown in FIG. 1B schematically). The regulating plate 150 includes a plurality of mesh openings 152 and a plurality of metal sheets 154, and at least part of the metal sheets 154 is electrically connected to the cathode 130. Here, the materials and types of the electroplating tank 110, the electrolyte 112, the anode 120, and the cathode 130 may be adjusted according to the type of the actual metal to be plated (e.g., copper), which is not limited in the disclosure. In addition, the metal sheets 154 electrically connected to the cathode 130 may have the same reducing metal mechanism as the cathode 130. Other details of the electroplating apparatus 100 are described further below.
Next, a substrate S to be plated is fixed on the cathode 130 (step S200). After the power supply 140 supplies power, a plurality of power lines L are formed between the anode 120 and the cathode 130 (which may be in the moving direction of electrons released after the anode 120 is powered on), and the power lines L move from the anode 120 to the cathode 130 (step S300). Next, part of the power lines L (such as the power line L1 in FIG. 1B) drives part of the metal ions Y in the electrolyte 112 to pass through the regulating plate 150 and form a first metal plating layer 10 on the to-be-plated substrate S (step S400). Another part of the power lines L (L2 in FIG. 1B) drives another part of the metal ions Y in the electrolyte 112 to form a second metal plating layer 20 on the regulating plate 150 (step S500). Here, the power lines L may be emitted from the anode 120 in parallel uniformly, and the power lines L also reach the to-be-plated substrate S in parallel uniformly.
Accordingly, with the design of the regulating plate 150 between the anode 120 and the cathode 130 in the electroplating apparatus 100 of the present embodiment, part of the power lines L (the power lines L1) moving from the anode 120 to the cathode 130 drives part of the metal ions Y in the electrolyte 112 to pass through the mesh openings 152 of the regulating plate 150 to form a metal plating layer on the to-be-plated substrate S (the first metal plating layer 10), whereas another part of the power lines L (the power line L2) drives another part of the metal ions Y in the electrolyte 112 to form a metal plating layer (the second metal plating layer 20) on the metal sheets 154 of the regulating plate 150. In this way, the power lines L may be redistributed, and the part where circuits are formed on the to-be-plated substrate S has a consistent density of the power lines, thereby resolving the problem of poor plating thickness uniformity of the metal plating layer (the first metal plating layer 10) on the to-be-plated substrate S.
In some embodiments, the metal ions Y may be copper ions (Cu²⁺), so the first metal plating layer 10 on the to-be-plated substrate S and the second metal plating layer 20 on the regulating plate 150 may be reduced copper, but the disclosure is not limited thereto.
In this embodiment, the mesh openings 152 are part of an insulating mesh panel 30, the metal sheets 154 are disposed on the insulating mesh panel 30, and the metal sheets 154 are all electrically connected to the cathode 130, so that the metal sheets 154 are coated with the second metal plating layer 20. Furthermore, the manufacturing process of the regulating plate 150 of the present embodiment includes, for example, the following steps. First, an insulating mesh panel 30 having substantially the same size as the to-be-plated substrate S is provided, and the insulating mesh panel 30 includes the mesh lines 32 and the mesh openings 152 defined by the mesh lines 32. Next, metal plates (such as a full copper plate) are adhered to the insulating mesh panel 30. Then, a pattern as requested is formed by etching, and a nickel-gold or nickel-palladium-gold or other metal protective layer (not shown) is plated. The protective layer will not be attacked by the etching solution and is used as a stop barrier when the copper plating is to be stripped later (as in the pattern formed by the metal sheets 154 in FIG. 1C). Alternatively, the metal plates directly made of metal (e.g., stainless steel) that cannot be etched by the etching solution are adhered to the insulating mesh panel 30 after the pattern is made, such that the metal protective layer is not required.
Furthermore, the to-be-plated substrate S may include a dry film 40 having a plurality of openings 42. The metal corresponding to the position of the opening 42 of the dry film 40 is etched away (and the mesh openings 152 may be aligned with the openings 42) to allow the electric power line L to pass through, while the metal corresponding to the position of covering portions 44 of the dry film 40 are retained and in electrical connection with the cathode 130, so that the power line L drives the metal ions Y to be plated and the power line L terminates at the metal sheets 154. Therefore, the shape of the mesh openings 152 and the shape of the metal sheets 154 may be complementary, but the disclosure is not limited thereto. Here, the material of the dry film 40 is, for example, an insulating material.
It should be noted that the regulating plate of the disclosure is not limited to the above configuration of the regulating plate 150. Please refer to both FIG. 1C and FIG. 1D. The regulating plate may also be replaced with a regulating plate 150A of another embodiment. Different from the regulating plate 150, the regulating plate 150A is provided with a plurality of metal sheets 154A disposed in arrays on the insulating mesh panel 30; while part of the metal sheets 154A is electrically connected to the cathode 130, other part of the metal sheets 154A is not electrically connected to the cathode 130. In other words, only part of the metal sheets 154A is electrically connected to the cathode 130, so that only part of the metal sheets 154A is formed with the second metal plating layer 20.
Furthermore, in the embodiment of FIG. 1C, only the mesh openings 152 may form channels to allow the power lines L and the metal ions Y to pass through. In other words, the power lines L and the metal ions Y do not pass through the metal sheets 154. In the embodiment of FIG. 1D, each of the metal sheets 154A includes at least one hole H, and the holes H of the metal sheets 154A without the second metal plating layer 20 formed thereon (namely, the metal sheets 154A that are not electrically connected to the cathode 130) may form channels with the mesh openings 152 (while part or all of the other mesh openings 152 also form channels on their own). Here, although the hole H is shown to be circular in FIG. 1D, the disclosure does not limit the shape of the hole H thereto, as the hole H may also be in the shape of, for example, a rectangle or a polygon. The number of the holes H in each metal sheet 154A is also not limited to one, as the number of holes H may be determined depending on the actual design requirements. In addition, in the embodiment of FIG. 1D, the metal sheets 154A are, for example, steel sheets or elements made by other metal less likely to be etched. And it is also possible that one metal sheet 154A is configured to correspond to a plurality of mesh openings 152, but the disclosure is not limited thereto.
In some embodiments, the electroplating apparatus 100 further includes a plurality of wires 160 connected to the metal sheets 154/metal sheets 154A one-to-one. Note that FIG. 1C and FIG. 1D only schematically show the wires 160 and do not show the actual connection details between the wires 160 and the metal sheets 154/metal sheets 154A.
Moreover, the electroplating apparatus 100 in the embodiment of FIG. 1C further includes a controller 170 connected to the wires 160, so that the currents of the wires 160 may be collected to the cathode 130 by the controller 170. The controller 170 in the embodiment of FIG. 1D may be further configured to control electrical connection states of the wires 160. For example, the controller 170 conducts only part of the wires 160 (the metal sheets 154A are electrically connected to the cathode 130), so that only part of the metal sheets 154A is formed with the second metal plating layer 20. In other words, the controller 170 does not conduct the other part of the wires 160 (the metal sheets 154A are not electrically connected to the cathode 130). Therefore, the second metal plating layer 20 is not formed on the said other part of the metal sheets 154A, and the power line L passes through the holes H on the metal sheets 154A, but the disclosure is not limited thereto.
In some embodiments, the part where circuits are formed on the to-be-plated substrate S includes a circuit dense area and a circuit empty area (both not shown). As the problem of poor plating thickness uniformity of the metal plating layer is severer in the circuit dense area, the electroplating apparatus 100 of the present embodiment may resolve the problem of poor electroplating thickness uniformity of the metal plating layer more significantly in the circuit dense area of the to-be-plated substrate S, but the disclosure is not limited thereto; effects may also be seen in the circuit empty area.
In some embodiments, the to-be-plated substrate S may further include a seed layer 50, and the first metal plating layer 10 may be plated on the seed layer 50, but the disclosure is not limited thereto.
In some embodiments, the shape of the mesh opening 152 may also be determined by the actual design requirements, as the disclosure does not limit the shapes of the elements.
In some embodiments, the distance between the regulating plate 150 and the to-be-plated substrate S may be range from 2 mm to 5 cm, but the disclosure is not limited thereto.
In some embodiments, the electroplating apparatus 100 further includes a chuck 180 and a nozzle (not shown), and the chuck 180 is configured to clamp the to-be-plated substrate S, and the nozzle is configured to improve the problem of metal ion mass transmission, but the disclosure is not limited thereto.
In some embodiments, the metal plating layer formed on the regulating plate may be stripped using an etching solution after the electroplating is completed, so that the regulating plate may be reused and the overall electroplating cost may be reduced, but the disclosure is not limited thereto.
To sum up, with the design of a regulating plate between the anode and the cathode in the electroplating apparatus of the disclosure, part of the power lines moving from the anode to the cathode may drive part of the metal ions in the electrolyte to pass through the mesh openings of the regulating plate and form a metal plating layer on the to-be-plated substrate, whereas another part of the of power lines may drive another part of the metal ions in the electrolyte to form a metal plating layer on the metal sheets on the regulating plate. With this configuration, the power lines may be redistributed, and the part where circuits are formed on the to-be-plated substrate has a consistent density of the power lines, thereby resolving the problem of poor plating thickness uniformity of the metal plating layer on the to-be-plated substrate.
Although the disclosure has been disclosed as above with examples, it is not intended to limit the disclosure. Anyone with ordinary knowledge in the technical field can make changes and modifications without departing from the spirit and scope of the disclosure. The protection scope of the disclosure shall be determined by the scope of the appended patent application.

Claims

What is claimed is:

1. An electroplating apparatus, comprising:

an electroplating tank, accommodating electrolyte;

an anode and a cathode, both disposed in the electroplating tank;

a power supply, electrically connected to the anode and the cathode; and

a regulating plate, disposed between the anode and the cathode, and comprising a plurality of mesh openings and a plurality of metal sheets, wherein at least part of the metal sheets is electrically connected with the cathode.

2. The electroplating apparatus as claimed in claim 1, wherein the mesh openings are part of an insulating mesh panel, the metal sheets are disposed on the insulating mesh panel, and the metal sheets are all electrically connected with the cathode.

3. The electroplating apparatus as claimed in claim 2, wherein channels are only formed by the mesh openings.

4. The electroplating apparatus as claimed in claim 2, further comprising a plurality of wires connecting to the metal sheets one-to-one.

5. The electroplating apparatus as claimed in claim 4, further comprising a controller connected to the wires, wherein currents of the wires are collected to the cathode by the controller.

6. The electroplating apparatus as claimed in claim 2, wherein a shape of the mesh openings are complementary to a shape of the metal sheets.

7. The electroplating apparatus as claimed in claim 1, wherein the mesh openings are part of an insulating mesh panel, the metal sheets are disposed into arrays on the insulating mesh panel, part of the metal sheets is electrically connected to the cathode, and an other part of the metal sheets is not electrically connected to the cathode.

8. The electroplating apparatus as claimed in claim 7, wherein each of the metal sheets comprises at least one hole, and the at least one hole and the mesh openings form channels.

9. The electroplating apparatus as claimed in claim 7, further comprising a plurality of wires connecting to the metal sheets one-to-one.

10. The electroplating apparatus as claimed in claim 9, further comprising a controller connected with the wires, wherein the controller is configured to control electrical connection states of the regulating plate.

11. An electroplating method, comprising:

providing an electroplating apparatus, wherein the electroplating apparatus comprises:

an electroplating tank, accommodating electrolyte;

an anode and a cathode, both disposed in the electroplating tank;

a power supply, electrically connected to the anode and the cathode;

a regulating plate, disposed between the anode and the cathode, and comprising a plurality of mesh openings and a plurality of metal sheets, wherein at least part of the metal sheets is electrically connected to the cathode;

fixing a to-be-plated substrate on the cathode;

after the power supply supplies power, forming a plurality of power lines between the anode and the cathode, wherein the power lines move from the anode to the cathode;

forming a first metal plating layer on the to-be-plated substrate, as part of the power lines drives part of metal ions in the electrolyte to pass through the regulating plate; and

forming a second metal plating layer on the regulating plate, as another part of the power lines drives another part of the metal ions in the electrolyte.

12. The electroplating method as claimed in claim 11, wherein the mesh openings are part of an insulating mesh panel, the metal sheets are disposed on the insulating mesh panel, and the metal sheets are all electrically connected with the cathode to form the second metal plating layer on all of the metal sheets.

13. The electroplating method as claimed in claim 12, wherein a shape of the mesh openings are complementary to a shape of the metal sheets.

14. The electroplating method as claimed in claim 12, wherein the electroplating apparatus further comprises a plurality of wires connecting to the metal sheets one-to-one.

15. The electroplating method as claimed in claim 14, wherein the electroplating apparatus further comprises a controller connected with the wires, wherein currents of the wires are collected to the cathode by the controller.

16. The electroplating method as claimed in claim 12, wherein the to-be-plated substrate comprises a dry film having a plurality of openings, and the mesh openings are aligned with the openings.

17. The electroplating method as claimed in claim 11, wherein the mesh openings are part of an insulating mesh panel, the metal sheets are disposed into arrays on the insulating mesh panel, and only part of the metal sheets is electrically connected to the cathode to form the second metal plating layer only on part of the metal sheets.

18. The electroplating method as claimed in claim 17, wherein each of the metal sheets comprises at least one hole, and the at least one hole of the metal sheets without the second metal plating layer forms channels with the mesh openings.

19. The electroplating method as claimed in claim 17, wherein the electroplating apparatus further comprises a plurality of wires electrically connected to the metal sheets one-to-one.

20. The electroplating method as claimed in claim 19, wherein the electroplating apparatus further comprises a controller configured to control electrical connection states of the wires.