Electrolytic plating equipment

Abstract

The present invention discloses an electrolytic plating apparatus comprising a membrane frame having a through hole at its center, a plurality of transport branch pipes extending from the sidewall of the through hole of the membrane frame to the edge of the membrane frame, and a plating solution buffer structure including a center cap and a flow rate stabilizing sleeve. In the electrolytic plating apparatus, the center cap is provided on the through hole of the membrane frame and covers the through hole. A plurality of first holes are formed in the upper part of the center cap. A flow rate stabilizing sleeve is fixed below the center cap and inserted into the through hole of the membrane frame. At least one second hole is formed in the sidewall of the flow rate stabilizing sleeve. The electrolytic plating apparatus further comprises a diffusion plate fixed to the upper part of the membrane frame and having a plurality of third holes. The present invention can moderate the flow rate of the fluid, thus effectively solving the problem of the difference between the center and the edge of the substrate being electroplated.

Description

[Technical field]

[0001] The present invention relates to the technical field of semiconductor manufacturing, and more particularly to electrolytic plating equipment. [Background technology]

[0002] At present, flip chip packaging process is the mainstream process in the market, and 2.5D and 3D packages are gradually becoming mature and mass-produced in the market. In the field of electrolytic plating applications, it is particularly important to improve the uniformity of the solder product and suppress the coplanarity. If it can be improved effectively, it can greatly improve the reliability of the product, thereby enhancing the competitiveness of the product.

[0003] Currently, two types of plating methods are used in electrolytic plating of wafer level packages: horizontal plating and vertical plating. The equipment used for the two plating methods is a horizontal jet electrolytic plating machine and a vertical rack plating fixture. In the actual process, the vertical rack plating equipment is the conventional electrolytic plating equipment, and the horizontal jet electrolytic plating equipment is the electrolytic plating equipment improved after the vertical rack plating equipment, so the horizontal jet electrolytic plating equipment has the advantages of simple operation, good tank expandability, high degree of automation and so on. Its features, such as low risk of cross-contamination of plating solutions, easy management of plating solutions, reduced water consumption and costs, excellent operating environment, good product uniformity, and high reliability, have made it a suitable alternative to traditional vertical rack plating equipment for semiconductor manufacturers.

[0004] When a horizontal jet electroplating apparatus is used to electrolytically plate a substrate, the current density is non-uniform across the substrate, resulting in a film plated on the substrate with low uniformity and high coplanarity. If one attempts to increase the plating speed by simply increasing the flow rate of the plating solution without making structural improvements, the unevenness of the film will become even worse. In electrolytic plating equipment, the plating speed is primarily related to the flow rate of the plating solution across the substrate, although chemistry is a factor that affects the plating speed. To increase the plating speed, a large amount of plating solution must be supplied to the substrate in a stable manner. However, as the flow rate of the plating solution increases, it becomes more difficult to control the electric field across the substrate and the uniformity of the plating solution flow. In particular, when the plating solution is dispersed in the flow field of the electroplating apparatus by a fountain flow field, the momentum of the fountain flow field is strong in the center and relatively weak in the edge. How to control the stability of the flow field is a key point in how to improve the differentiation between the center and edge of the substrate being plated. Summary of the Invention

[0005] In order to better ensure the quality of substrate electrolytic plating and control the relative stability of the flow field, the present application proposes an electrolytic plating apparatus. The cathode plating solution passes through the transport branch pipe, enters between the flow stabilization sleeve and the side wall of the through hole in the center of the membrane frame, enters the inside of the flow stabilization sleeve through the second hole opening in the side wall of the flow stabilization sleeve, and is then supplied to the diffusion plate through the first hole in the central cap, thereby solving the problem of the flow field becoming unstable when the method of diffusing the plating solution in the flow field of the electrolytic plating device is the fountain type. It also solves the issue of variation between the center and edge of the packaged substrate product.

[0006] The electrolytic plating apparatus proposed by the present invention is A membrane frame having a through hole in the center; a transport branch pipe extending from a side wall of the through hole of the membrane frame to an edge of the membrane frame; A plating solution buffer structure having a center cap and a flow stabilizing sleeve; a central cap provided in the through hole of the membrane frame to cover the through hole, the central cap having a plurality of first holes at an upper portion thereof; a flow stabilizing sleeve disposed below the central cap, the flow stabilizing sleeve having at least one second hole in a side wall thereof and inserted into the through hole of the membrane frame; a diffusion plate provided on an upper portion of the membrane frame, the diffusion plate having a plurality of third holes; The cathode plating solution flows through a transport branch pipe into a space between the flow rate stabilizing sleeve and the side wall of the through hole of the membrane frame, enters the inside of the flow rate stabilizing sleeve through a second hole opening in the side wall of the flow rate stabilizing sleeve, is supplied to the diffusion plate through the first hole of the central cap, and reaches the substrate through a third hole on the diffusion plate.

[0007] In one embodiment of the present invention, the first hole on the center cap and the third hole on the diffuser plate may be arranged in the same manner.

[0008] In one embodiment of the present invention, the first hole on the center cap and the third hole on the diffuser plate may be arranged in different ways.

[0009] In one embodiment of the present invention, each first hole in the center cap may completely overlap with a corresponding third hole in the diffuser plate.

[0010] In one embodiment of the present invention, each first hole in the center cap may overlap a corresponding third hole in the diffuser plate.

[0011] In one embodiment of the present invention, each first hole in the center cap may not overlap at all with a corresponding third hole in the diffuser plate.

[0012] In one embodiment of the present invention, the first holes of the center cap and the third holes of the diffusion plate may all be arranged in a honeycomb pattern.

[0013] In one embodiment of the present invention, when the number of the second holes in the flow stabilizing sleeve is greater than one, the second holes in the flow stabilizing sleeve may be evenly distributed on the side wall of the flow stabilizing sleeve.

[0014] In one embodiment of the present invention, the connection between the transport branch and the through hole may correspond to a second hole on the flow stabilizing sleeve.

[0015] In one embodiment of the present invention, the connections between the transport branches and the through holes may be arranged in a staggered manner with the second holes on the flow stabilizing sleeve.

[0016] In one embodiment of the present invention, the centers of the second holes may all be on the same horizontal line.

[0017] In one embodiment of the present invention, the centers of the second holes may be on a different horizontal line.

[0018] In one embodiment of the present invention, the diameters of the first holes on the central cap may be equal.

[0019] In one embodiment of the present invention, the first holes on the center cap may have different diameters.

[0020] The electrolytic plating apparatus of the present invention employs a method in which the cathode plating solution is transported via a transport branch pipe so that the cathode plating solution enters the space formed between the side wall of the flow rate stabilizing sleeve and the through hole at the center of the membrane frame, i.e., the first storage space, and the cathode plating solution enters the second storage space in the internal space of the flow rate stabilizing sleeve through a second hole opening into the side wall of the flow rate stabilizing sleeve, and is then supplied to the diffusion plate through the first hole in the central cap. This effectively prevents the cathode plating solution from spurting out directly upward from the central through-hole of the membrane frame, affecting the plating uniformity in the central area of ​​the substrate, successfully moderates the fluid velocity, effectively resolves the difference between the center and edge of the plated substrate, and improves the quality of the electrolytically plated product. Additional features and advantages of the invention will be set forth in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and obtained by the structure particularly illustrated in the specification and the accompanying drawings. [Brief description of the drawings]

[0021] In order to describe the embodiments of the present invention and the technical solutions in the prior art more clearly, the drawings that need to be used in the description of the embodiments and the prior art are briefly introduced below. The following drawings are obviously some of the embodiments of the present invention. Those skilled in the art can derive other drawings based on these drawings without any creative effort. [Figure 1] FIG. 1 is a schematic diagram showing a partial structure of an electrolytic plating apparatus according to one embodiment of the present invention. [Diagram 2] FIG. 2 is a top view of a membrane frame according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a bottom view of a membrane frame according to one embodiment of the present invention. [Figure 4] FIG. 4 is a perspective view of a plating solution buffer structure according to one embodiment of the present invention. [Diagram 5] FIG. 5 is a top view of a plating solution buffer structure according to an embodiment of the present invention. [Figure 6] FIG. 6 is a bottom view of a plating solution buffer structure according to an embodiment of the present invention. [Figure 7] FIG. 7 is a schematic diagram of a partial structure of a plating solution buffer structure and a membrane frame assembly in an embodiment of the present invention. [Figure 8] FIG. 8 is a top view of a diffuser plate according to one embodiment of the present invention. [Figure 9] FIG. 9 is a bottom view of a diffuser plate according to an embodiment of the present invention. [Figure 10] FIG. 10 is a schematic diagram of fluid delivery in one embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] In order to make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described hereinafter with reference to the drawings in the embodiments of the present invention. It is apparent that the described embodiments are some rather than all embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without any creative efforts shall fall within the scope of protection of the present invention.

[0023] During the packaging process of the substrate, when the plating solution is spread in the flow field of the electrolytic plating device using a fountain flow field, since the center of the fountain flow field is strong and the edges are relatively weak, it is necessary to control the relative stability of the flow field in order to better ensure the quality of the substrate plating. There is an urgent need to solve the problem of how to improve the differentiation between the center and edge of a packaged substrate product by controlling the stability of the flow field. The present application proposes an electrolytic plating apparatus that solves the problem of the flow field becoming unstable when the method of spreading the plating solution in the flow field of the electrolytic plating apparatus is a fountain flow field type, thereby also solving the problem of the difference between the center and edge of the packaged substrate product.

[0024] Please refer to Figures 1 and 3. FIG. 1 is a schematic diagram showing a partial structure of an electrolytic plating apparatus according to one embodiment of the present invention. FIG. 3 is a bottom view of a membrane frame according to one embodiment of the present invention. As shown in FIGS. 1 and 3, the electrolytic plating apparatus includes a membrane frame 100, a transport branch pipe 200, a plating solution buffer structure 300, and a diffusion plate 400. A through hole 101 is opened at the center of the membrane frame 100, and a plating solution buffer structure 300 is provided within the through hole 101. The transport branch pipe 200 is provided in the membrane frame 100 . The transport branch pipe 200 extends from the center to the end of the membrane frame 100 , and a diffusion plate 400 is fixed above the membrane frame 100 .

[0025] Please refer to Figures 1 to 3. Figure 2 is a top view of a membrane frame according to an embodiment of the present invention. As shown in Figures 2 and 3, the membrane frame 100 is a generally dish-shaped, rigid, perforated or mesh frame structure. In the actual process, a membrane 500 is fixed below the membrane frame 100 . Film 500 is a cationic film used in the electrolytic plating of copper, nickel, and tin. The membrane may be a proton exchange membrane or a conventional membrane covered with a fabric structure suitable for alloy plating. The membrane frame 100 is also provided with a number of transport branches 200 that extend from the side walls of the through-hole 101 in the center of the membrane frame 100 to the edges of the membrane frame 100 .

[0026] The transport branches 200 are distributed over the structure of the membrane frame 100 . When the number of transport branches 200 is two or more, the transport branches 200 are evenly distributed in the membrane frame 100 . The uniform distribution of the transport branches 200 can ensure that the cathodic plating solution enters the through-holes 101 from different directions evenly, and the overall flow rate is kept stable. One end of the transport branch pipe 200 is connected to a through hole 101 located at the center of the membrane frame 100, and serves as an outlet for the cathode plating solution. The other end of the transport branch pipe 200 is fixedly connected to the side wall of the membrane frame 100. The bottom wall of the transport branch pipe 200 is provided with a plating solution inlet 201 which is used as an inlet for a cathode plating solution. The plating solution inlet 201 is connected to a liquid inlet pipe (not shown) for the cathode plating solution provided at the bottom of the membrane frame 100 . In one embodiment, the number of transport branches 200 is six, which are radially arranged on the structure of the membrane frame 100 .

[0027] When electrolytic plating is performed in the central region of a substrate, it is difficult to control the uniformity of the flow of plating solution, especially in the central region of the substrate. When the plating solution is diffused in the flow field of the electrolytic plating equipment using a fountain flow field, the momentum of the fountain flow field is strong in the center and weak at the edges, which makes the flow field of the electrolytic plating equipment unstable and affects the effect of electrolytic plating. Therefore, in the embodiment of the present invention, a plating solution buffer structure 300 is provided in the center of the membrane frame 100 .

[0028] Please refer to Figures 4 to 6. FIG. 4 is a perspective view of a plating solution buffer structure according to one embodiment of the present invention. FIG. 5 shows a top view of a plating solution buffer structure according to an embodiment of the present invention. FIG. 6 is a bottom view of a plating solution buffer structure according to an embodiment of the present invention. As shown in FIGS. 4 to 6, the plating solution buffer structure 300 includes a central cap 301 and a flow rate stabilizing sleeve 302 .

[0029] The central cap 301 is fixed to the through hole 101 of the membrane frame 100 and covers the through hole 101 of the membrane frame 100 . The upper portion of the central cap 301 is provided with a plurality of first holes 3011 . The plurality of first holes 3011 are arranged in a honeycomb pattern and are used to distribute the flow to the diffusion plate 400 evenly. The diameters of the multiple first holes 3011 may be completely the same or may be different. Consider that a corresponding chuck (not shown) directly above the diffuser plate 400 drives the wafer (not shown) in a horizontal rotational motion during the electroplating process. The closer the wafer is to the edge, the greater the linear velocity, while the linear velocity at the center of the wafer is nearly zero. As the liquid passes through the diffuser plate 400 and reaches the wafer, it travels further towards the edge of the wafer. Therefore, to ensure that the flow rate of the liquid is uniform when it reaches the wafer, first, more liquid needs to be kept flowing to reach the center of the diffuser plate 400, and therefore more liquid needs to flow to the center of the central cap 301. When the diameters of the multiple first holes 3011 are different, the diameters of the first holes 3011 become gradually smaller in a direction extending from the center of the central cap 301 to the edge thereof. In one embodiment, the diameters of the plurality of first holes 3011 are all the same. The diameter of the first hole 3011 is 0.8 to 3.0 mm. The density of the first holes 3011 gradually decreases in a direction extending from the center to the edge of the central cap 301 . In yet another embodiment, the density of the first holes 3011 is the same in a direction extending from the center to the edge of the central cap 301. The diameters of the first holes 3011 are gradually decreased in a direction extending from the center to the edge of the central cap 301. The diameter of the first hole 3011 is 3.0 to 0.8 mm.

[0030] A flow stabilizing sleeve 302 is connected to the lower end surface of the center cap 301 . The flow stabilizing sleeve 302 has at least one second hole 3021 opening in its side wall. During installation, the flow stabilization sleeve 302 is inserted into the through hole 101 of the membrane frame 100 . During the assembly process, please refer to Figure 7. Figure 7 shows a schematic diagram of a partial structure of the plating solution buffer structure and membrane frame assembly in an embodiment of the present invention. As shown in FIG. 7, the space formed between the flow rate stabilization sleeve 302 and the side wall of the through-hole 101 of the membrane frame 100 is a first accommodating space 600 , and the internal space of the flow rate stabilization sleeve 302 is a second accommodating space 700 . The cathode plating solution outlet of the transport branch pipe 200 and the second hole 3021 of the flow rate stabilizing sleeve 302 can be arranged in a corresponding manner or in a staggered manner. During the actual process, after the cathode plating solution enters the first accommodating space 600, it enters the second accommodating space 700 through the second hole 3021, and then sprays out through the first hole 3011 opening in the central cap 301, thereby achieving the effect of cushioning the impact of the plating solution.

[0031] When the number of the second holes 3021 on the side wall of the flow stabilization sleeve 302 is greater than one, the second holes 3021 are evenly distributed on the side wall of the flow stabilization sleeve 302 . When multiple second holes 3021 are provided, the centers of the multiple second holes 3021 can be set on the same horizontal line, or the centers of different second holes 3021 can be set on horizontal lines at different heights. When the centers of the multiple second holes 3021 are arranged on horizontal lines at different heights, the plating solution flowing from the first accommodating space 600 to the second accommodating space 700 can be further improved from being stratified, and the sudden changes in the flow rate can be mitigated and stabilized, thereby maintaining a smooth and stable effect.

[0032] In an actual process, the cathode plating solution is transported from a cathode plating solution inlet pipe (not shown) to the transport branch pipe 200 via the plating solution inlet 201, and reaches the first accommodating space 600 through the transport branch pipe 200. The solution then flows into the second accommodating space 700 in the flow rate stabilizing sleeve 302 through the second hole 3021 opening into the side wall of the flow rate stabilizing sleeve 302, and is evenly transported to the diffusion plate 400 via the multiple first holes 3011 opening into the central cap 301, where the substrate is processed.

[0033] Please refer to Figures 8 to 9. FIG. 8 shows a top view of a diffuser plate according to one embodiment of the present invention. FIG. 9 shows a bottom view of a diffuser plate according to an embodiment of the present invention. As shown in FIGS. 8 and 9, a diffusion plate 400 is provided on the upper part of the membrane frame 100, and the diffusion plate 400 is provided with a plurality of third holes 401. The diffusion plate 400 can redistribute the electric field and flow field between the anode and the cathode through the multiple third holes 401, so that the electric field and flow field between the anode and the cathode are more uniformly distributed. The third holes 401 are arranged in a honeycomb pattern, and the diameters of the third holes 401 may be completely the same or different. In one embodiment, the diameters of the third holes 401 distributed in the diffuser plate 400 are equal. For example, the diameter of the third hole 401 is 0.8 to 3.0 mm. The diameter of the third hole 401 is 2.0 mm. In yet another embodiment, the diameters of the third holes 401 distributed in the diffuser plate 400 are not uniform. The diameter of the third holes 401 is gradually decreased from the center to the edge of the diffusion plate 400, and is 3.0 to 0.8 mm. The material of the diffuser plate 400 may be polyvinyl chloride, polypropylene, polyetheretherketone, polyvinylidene fluoride, soluble polytetrafluoroethylene, Teflon, and the like.

[0034] In an actual process, the positional relationship between the first holes 3011 provided in the central cap 301 and the third holes 401 provided in the diffusion plate 400 may be such that each first hole 3011 is perfectly aligned with the corresponding third hole 401. Moreover, each of the first holes 3011 may partially overlap with the corresponding third hole 401, or each of the first holes 3011 may not overlap with the corresponding third hole 401 at all. When each first hole 3011 completely overlaps with a corresponding third hole 401 , the diameter and arrangement of the first holes 3011 are completely the same as the diameter and arrangement of the third holes 401 . For example, when the first holes 3011 completely overlap with the corresponding third holes 401, the diameters of the first holes 3011 and the third holes 401 are 2.0 mm, and the arrangement is a honeycomb arrangement. Please refer to Figure 10. FIG. 10 is a schematic diagram of fluid delivery in one embodiment of the present invention. As shown in FIG. 10, when the first holes 3011 completely overlap with the corresponding third holes 401, the fluid passes directly through the diffuser plate 400 from the center cap 301 to the substrate without any obstruction, so that the substrate is electroplated. In this case, electrolytic plating is more efficient and more uniform.

[0035] In the actual process, the cathodic plating solution flows out of the cathode cell, passes through a membrane and a degasser, and enters the plating chamber. The cathode plating solution entering the plating chamber enters the transport branch pipe 200 through the cathode plating solution inlet 201 , is transported through the transport branch pipe 200 to the cathode plating solution outlet, and flows into the first accommodating space 600 . The cathode plating solution passes through the second hole 3021 opening into the flow rate stabilization sleeve 302 and enters the second storage space 700 in the flow rate stabilization sleeve 302, then sprays out through the first hole 3011 opening into the central cap 301, reaches the diffusion plate 400, and is diffused on the diffusion plate 400. The cathodic plating solution passes through the plurality of third holes 401 on the diffusion plate 400 to reach the substrate, and an electrolytic plating process is carried out on the substrate. By disposing the plating solution buffer structure 300, it can effectively prevent the cathode plating solution from directly spurting out from the central through-hole 101 of the membrane frame 100, which affects the uniformity of the electrolytic plating in the central area of ​​the substrate, and effectively moderate the flow rate of the fluid, improving the plating process environment of the wafer-level package, and effectively resolving the difference between the center and the edge of the plated substrate. The quality of electrolytic plating products is improved.

[0036] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions described in these embodiments can be modified, and some technical features can be replaced with equivalents. These modifications or replacements do not cause the essence of the corresponding technical solutions to depart from the spirit and scope of the technical solutions of each embodiment of the present invention.

Claims

1. An electrolytic plating apparatus comprising: A membrane frame having a through hole in the center; a transport branch pipe extending from a side wall of the through hole of the membrane frame to an edge of the membrane frame; A plating solution buffer structure having a center cap and a flow stabilizing sleeve; a central cap provided in the through hole of the membrane frame and covering the through hole, the central cap having a plurality of first holes at an upper portion thereof; a flow stabilizing sleeve disposed below the central cap, the flow stabilizing sleeve having at least one second hole in a side wall thereof and inserted into a through hole in the membrane frame; and a diffusion plate provided on an upper portion of the membrane frame, the diffusion plate having a plurality of third holes; an electrolytic plating apparatus, characterized in that a cathode plating solution flows through the transport branch pipe into a space between the flow rate stabilizing sleeve and the side wall of the through hole of the membrane frame, enters the inside of the flow rate stabilizing sleeve through the second hole opening in the side wall of the flow rate stabilizing sleeve, is supplied to the diffusion plate through the first hole of the central cap, and reaches a substrate through the third hole on the diffusion plate.

2. 2. The electrolytic plating apparatus of claim 1, wherein the first hole on the center cap and the third hole on the diffusion plate are arranged in the same manner.

3. 2. The electrolytic plating apparatus of claim 1, wherein the first hole on the center cap and the third hole on the diffusion plate are arranged in different ways.

4. 3. The electrolytic plating apparatus of claim 2, wherein each of said first holes in said center cap completely overlaps with a corresponding third hole in said diffuser plate.

5. 3. The electrolytic plating apparatus of claim 2, wherein each of the first holes in the center cap overlaps a corresponding third hole in the diffuser plate.

6. 3. The electrolytic plating apparatus of claim 2, wherein each of the first holes in the center cap does not overlap with a corresponding third hole in the diffusion plate.

7. 3. The electrolytic plating apparatus according to claim 2, wherein the first holes of the center cap and the third holes of the diffusion plate are all arranged in a honeycomb pattern.

8. 2. The electrolytic plating apparatus according to claim 1, characterized in that when the number of the second holes of the flow rate stabilizing sleeve is greater than one, the second holes of the flow rate stabilizing sleeve are evenly arranged on the side wall of the flow rate stabilizing sleeve.

9. 2. The electrolytic plating apparatus according to claim 1, wherein the connection between the transport branch pipe and the through hole corresponds to the second hole on the flow stabilizing sleeve.

10. 2. The electrolytic plating apparatus of claim 1, wherein the connections between the transport branches and the through holes are staggered with the second holes on the flow stabilizing sleeve.

11. 2. The electrolytic plating apparatus according to claim 1, wherein the centers of said second holes are all on the same horizontal line.

12. 2. The electrolytic plating apparatus of claim 1, wherein the centers of the second holes are on different horizontal lines.

13. 2. The electrolytic plating apparatus of claim 1, wherein said first holes on said center cap have equal diameters.

14. 2. The electrolytic plating apparatus of claim 1, wherein the first holes on the center cap have different diameters.

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