A hanger assembly for an electroplating machine.

Abstract

This utility model relates to the field of semiconductor packaging manufacturing technology, and in particular to a rack assembly for an electroplating machine, including a rack base plate and a rack back cover; the rack base plate has an annular step, and a plurality of first bolt holes are evenly arranged on the outer periphery of the annular step; the rack back cover includes a main body area and an edge area; the main body area has a circular groove and an annular protrusion, the circular groove has a scratch-resistant rubber pad, and the annular protrusion has a crystal back pressing ring on its outer periphery; the edge area has second bolt holes; the edge area has a first annular groove, and a back cover sealing ring is installed in the first annular groove; the thickness of the edge area is thinned to a depth of 0.8 mm and a width of 40 mm. Through the thinning design, the central area of ​​the rack back cover can be further pressed down when tightened, thereby enhancing the tightness of the wafer pressing, effectively reducing water stains during the electroplating process, improving the surface flatness of the product, reducing the risk of equipment malfunction and product damage, and improving the production yield.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging manufacturing technology, and in particular to a hanger assembly for an electroplating machine. Background Technology

[0002] In semiconductor gold bump manufacturing, electroplating is a crucial step in forming metal bumps. Traditional electroplating processes typically include sputtering, photoresist coating, exposure, development, gold plating, photoresist removal, and metal layer etching. During the gold plating step, the wafer is mounted on a dedicated rack and immersed in the plating solution for metal deposition. Existing racks are usually secured with a base plate and a back cover by bolts, clamping the wafer between them. However, in actual production, it has been found that due to limitations in the rack's back cover design, the edge area is relatively thick, resulting in insufficient downward pressure in the central area of ​​the back cover during locking. This leads to insufficient tightness of the sealing ring on the back cover against the back of the wafer. This problem easily results in small droplets or water stains remaining on the back of the wafer and the conductive area of ​​the rack after electroplating, which in turn affects the vacuum adsorption effect during wafer removal, frequently triggering vacuum alarms and even causing wafer breakage. Furthermore, insufficient tightness can also cause a decrease in the uniformity of the electroplated layer, resulting in a product surface flatness that fails to meet high-quality requirements and increasing the defect rate in subsequent processes. Therefore, it is necessary to improve the existing electroplating rack structure to enhance its pressing performance and process stability. Utility Model Content

[0003] The purpose of this utility model is to provide a hanger assembly for an electroplating machine to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: a hanger assembly for an electroplating machine, comprising a hanger base plate and a hanger rear cover; the hanger base plate is provided with an annular step for supporting wafers, and a plurality of first bolt holes are evenly arranged on the outer periphery of the annular step; the hanger rear cover includes a main body area located in the center and an edge area surrounding the main body area; the main body area is provided with a circular groove and an annular protrusion, the circular groove is provided with a scratch-resistant rubber pad, and the annular protrusion is provided with a wafer back pressing ring on its outer periphery; the edge area is provided with second bolt holes corresponding to the positions of the first bolt holes; the edge area is also provided with a first annular groove, and a rear cover sealing ring is installed in the first annular groove; the thickness of the edge area is thinned, the thinning depth of the edge area is 0.8 mm, and the thinning width is 40 mm.

[0005] Preferably, a second annular groove is provided on the annular step, and a bottom plate sealing ring is installed in the second annular groove.

[0006] Preferably, the bracket base plate and the bracket rear cover are fastened together by bolts passing through the second bolt hole and the first bolt hole.

[0007] Preferably, the thickness of the crystal back pressing ring is 3.3 mm.

[0008] Preferably, the diameter of the anti-scratch pad is 185mm.

[0009] Preferably, the diameter of the back cover of the hanger is 280mm.

[0010] Compared with existing technologies, this utility model provides a hanger assembly for an electroplating machine, which has the following beneficial effects: By optimizing the structure by locally thinning the edge area of ​​the hanger's rear cover, the central area of ​​the rear cover is further pressed down when the hanger is locked, thereby significantly enhancing the tightness of the seal between the wafer and the rear cover sealing ring. This design effectively prevents electroplating solution or water stains from intruding into the back side of the wafer and the contact area, reducing water stain residue after electroplating, and thus avoiding abnormal vacuum adsorption and wafer breakage caused by liquid residue. At the same time, the more uniform and tighter seal helps to improve the uniformity of current distribution during electroplating, thereby improving the flatness and consistency of gold bump growth and improving product surface quality. In addition, this structural improvement is simple and reliable, requiring no changes to the original installation and operation procedures, with low implementation costs. It can significantly improve the normal operating time and capacity utilization of the equipment, reduce production interruptions and defective products, and has strong practicality and promotional value. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of the hanging bracket base plate of this utility model; Figure 2 This is a schematic diagram of the structure of the back cover of the hanging bracket of this utility model; Figure 3 This is a cross-sectional view of the present invention.

[0012] Explanation of reference numerals in the attached drawings: 1. Hanger base plate; 11. Annular step; 111. Second annular groove; 1111. Base plate sealing ring; 2. Hanger rear cover; 21. Main body area; 211. Circular groove; 2111. Anti-scratch pad; 212. Annular protrusion; 22. Edge area; 221. First annular groove; 2211. Rear cover sealing ring; 3. Wafer; 4. First bolt hole; 5. Crystal back pressing ring; 6. Second bolt hole; 7. Bolt. Detailed Implementation

[0013] The technical solutions of the present utility model will now be described with reference to the accompanying drawings in the embodiments of the present utility model: like Figures 1 to 3As shown, this utility model provides a hanger assembly for an electroplating machine, including a hanger base plate 1 and a hanger rear cover 2. The hanger base plate 1 has an annular step 11, which supports the wafer 3, ensuring the wafer 3 is centered during assembly and preventing displacement. Multiple first bolt holes 4 are evenly arranged on the outer periphery of the annular step 11 for corresponding connection with the hanger rear cover 2. To further improve the sealing effect, a second annular groove 111 is formed on the annular step 11. A base plate sealing ring 1111 is installed in the second annular groove 111. This base plate sealing ring 1111 is generally made of a corrosion-resistant, highly elastic material (such as fluororubber or silicone rubber). When the wafer 3 is placed on the annular step 11, the base plate sealing ring 1111 contacts the back of the wafer 3, forming a sealing barrier that effectively prevents electroplating solution from seeping into the back of the wafer 3 from the base plate side.

[0014] The back cover 2 of the mounting bracket is generally disc-shaped, with a diameter of d1, preferably 280 mm, to accommodate the clamping requirements of standard-sized wafers. The back cover 2 includes a main body area 21 in the center and an edge area 22 surrounding the main body area 21. The main body area 21 has a circular groove 211 and an annular protrusion 212. An anti-scratch pad 2111 is disposed within the circular groove 211. The anti-scratch pad 2111 has a diameter of d2, preferably 185 mm, and is made of a soft, insulating, and chemically resistant elastic material (such as special rubber or engineering plastic). This anti-scratch pad 2111 contacts the non-circuit area on the front side of the wafer 3 during pressing, providing cushioning and protection to prevent the metal back cover 2 from directly scratching the surface of the wafer 3. A back pressing ring 5 is provided around the outer periphery of the annular protrusion 212. The thickness of the back pressing ring 5 is preferably 3.3 mm. The back pressing ring 5 is usually made of a sealing material with excellent elasticity. The back pressing ring 5 is mainly used to directly press the edge area of ​​the back side of the wafer 3 when locking, and works with the bottom plate sealing ring 1111 to achieve bidirectional sealing and prevent the electroplating solution from entering the back side of the wafer 3.

[0015] The edge region 22 is provided with a second bolt hole 6 corresponding to the position of the first bolt hole 4. The bracket base plate 1 and the bracket rear cover 2 are fastened together by bolts 7 passing through the second bolt hole 6 and the first bolt hole 4, thereby reliably clamping the wafer 3. A first annular groove 221 is also provided on the edge region 22. A rear cover sealing ring 2211 is installed in the first annular groove 221 to further enhance the edge seal when locked, preventing electroplating solution from seeping in from the outside.

[0016] The core structural improvement of this utility model lies in the localized thinning of the edge region 22 of the hanger back cover 2. Specifically, the thickness of the edge region 22 is reduced to a depth of 0.8 mm and a width of W, which is 40 mm. This thinning design reduces the local rigidity of the edge region 22. During the tightening of the bolts 7, when the hanger back cover 2 is under overall force, the central region (main body region 21) experiences downward displacement. This allows the crystal back pressing ring 5, along with its corresponding back cover sealing ring 2211 and bottom plate sealing ring 1111, to adhere more tightly to the wafer 3, significantly improving the overall tightness and uniformity of the bonding.

[0017] Assembly and working process: During actual assembly, wafer 3 is first placed on the annular step 11 of the bracket base plate 1, ensuring that the back of wafer 3 is in initial contact with the base plate sealing ring 1111. Then, the bracket back cover 2 is aligned and placed over wafer 3, and bolts 7 are passed through the second bolt hole 6 and the first bolt hole 4 in sequence, applying a uniform tightening force by alternating diagonal tightening. During the tightening process, due to the thinning design of the edge area 22, the tightening force is more effectively converted into downward pressure on the central area of ​​wafer 3, so that the back pressing ring 5, the back cover sealing ring 2211, and the base plate sealing ring 1111 are all fully compressed and form multiple reliable seals.

[0018] The beneficial effects of this utility model are: This structural optimization effectively solves the problems of insufficient central pressure and poor sealing caused by the uniform rigidity of the back cover in traditional racks. The tighter compression significantly reduces the intrusion and residue of plating solution or cleaning water on the back of the wafer and the contact area, thus avoiding vacuum adsorption failure, frequent alarms, and the resulting wafer breakage risks caused by liquid droplet residue. Simultaneously, the uniform compression pressure helps ensure stable and consistent electrical contact between the wafer and the rack throughout the electroplating process, improving the uniformity of electroplating current distribution, thereby enhancing the uniformity of gold bump plating thickness and surface smoothness, and increasing product yield. This improved solution is ingeniously structured, easy to implement, requires no changes to the overall shape and operation of existing racks, is cost-effective, and easily promoted and applied to existing production lines, possessing practical value for improving the stability and reliability of semiconductor electroplating processes.

[0019] The above embodiments are merely some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without inventive effort are within the scope of protection of this utility model.

Claims

1. A hanging bracket assembly for an electroplating machine, characterized in that: The device includes a bracket base plate (1) and a bracket back cover (2); the bracket base plate (1) is provided with an annular step (11) for supporting the wafer (3), and a plurality of first bolt holes (4) are evenly arranged on the outer periphery of the annular step (11); the bracket back cover (2) includes a main body area (21) located in the middle and an edge area (22) surrounding the main body area (21); the main body area (21) is provided with a circular groove (211) and an annular protrusion (212), and the circular groove (211) is provided with a protective The outer periphery of the annular protrusion (212) is provided with a crystal back pressing ring (5); the edge region (22) is provided with a second bolt hole (6) corresponding to the position of the first bolt hole (4); the edge region (22) is also provided with a first annular groove (221), and a rear cover sealing ring (2211) is installed in the first annular groove (221); the thickness of the edge region (22) is thinned, the thinning depth of the edge region (22) is 0.8mm, and the thinning width is 40mm.

2. The hanger assembly for an electroplating tool as recited in claim 1, wherein: A second annular groove (111) is provided on the annular step (11), and a bottom plate sealing ring (1111) is installed in the second annular groove (111).

3. The hanger assembly for an electroplating tool as recited in claim 1, wherein: The bracket base plate (1) and the bracket back cover (2) are fastened together by bolts (7) passing through the second bolt hole (6) and the first bolt hole (4).

4. The hanger assembly for an electroplating tool as recited in claim 1, wherein: The thickness of the crystal back pressing ring (5) is 3.3 mm.

5. The hanger assembly for an electroplating tool as recited in claim 1, wherein: The diameter of the anti-scratch pad (2111) is 185mm.

6. The hanger assembly for an electroplating tool as recited in claim 1, wherein: The diameter of the rear cover (2) of the bracket is 280mm.

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