Wafer electroplating sieve plate
By designing strip-shaped holes and a stirring section on the wafer plating sieve, the problem of excessively high plating bump height at the wafer notch was solved, achieving uniformity in plating bump height and improving the electrical interconnect quality and reliability of the chip.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-29
- Publication Date
- 2026-04-03
AI Technical Summary
In traditional electroplating equipment, the height of the electroplating bumps at the wafer notch is too high, resulting in uneven height of the electroplating bumps between the wafer notch and the non-notch, which affects the performance and reliability of the chip.
Design a wafer electroplating sieve plate with strip-shaped holes and a stirring section. The stirring section stirs the electroplating solution during the wafer electroplating process to adjust the uniformity of the electroplating protrusion height at the wafer notch and non-notch areas.
This achieves uniformity in the height of plating bumps at both notched and non-notched locations on the wafer, improving the uniformity of plating bump height and ensuring the electrical interconnect quality and mechanical reliability of the chip.
Smart Images
Figure CN224077579U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor packaging technology, and in particular to a wafer electroplating sieve plate. Background Technology
[0002] Wafer electroplating is a key process in semiconductor manufacturing for achieving metal interconnects and packaging. It involves electrochemically depositing metal layers (such as copper, nickel, or gold) on the wafer surface to form bumps. Bump plating, as a core step in advanced packaging, directly determines the quality of the electrical interconnection and mechanical reliability between the chip and the substrate. The bumps must be highly uniform to ensure the integrity of the solder joints in subsequent soldering processes.
[0003] The electroplating equipment consists of an electroplating tank, an anode system, a cathode fixture, a circulating filtration system, and a power control module. The wafer, serving as the cathode, is horizontally fixed in the fixture and current is conducted through a contact ring. The anode is made of a soluble metal (such as phosphor bronze balls) or an inert material (titanium plated with iridium). A guide plate is installed above the anode to evenly distribute the current and turbulence.
[0004] In traditional electroplating equipment, the presence of wafer markings at the wafer notch area leads to a more concentrated distribution of electric field lines to the chip, resulting in a higher height of the plating bumps at the notch and non-notch areas. This unevenness affects chip performance and reliability, causing issues such as inconsistent signal transmission delays and poor connections. Therefore, there is an urgent need for equipment that can improve the uneven height of plating bumps between the wafer notch and non-notch areas. Utility Model Content
[0005] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a wafer electroplating sieve plate to solve the problems in the prior art.
[0006] To achieve the above-mentioned and other related objectives, this utility model is obtained through the following technical solution.
[0007] This utility model provides a wafer electroplating sieve plate, which has a plurality of strip-shaped holes; the length direction of any of the strip-shaped holes is parallel to the linear reciprocating motion direction of the wafer electroplating sieve plate; except for the strip-shaped holes corresponding to the wafer notches, a plurality of stirring parts are also formed in the other strip-shaped holes; the plurality of stirring parts fill the corresponding strip-shaped holes to form a hollow structure.
[0008] In one embodiment, the wafer electroplating sieve plate has a circular or near-circular structure.
[0009] In one embodiment, the diameter of the wafer plating sieve is at least 24 mm larger than that of the wafer.
[0010] In one embodiment, the thickness of the wafer electroplating sieve is 4.5 to 5.5 mm.
[0011] In one embodiment, the outline of the strip hole is rectangular.
[0012] In one embodiment, the thickness of the wafer electroplating sieve plate is the same as the thickness of the stirring section.
[0013] In one embodiment, the stirring section (12) is formed with a stirring edge (121) perpendicular to the reciprocating motion direction.
[0014] In one embodiment, the maximum width d of the stirring edge (121) is 15-25 mm.
[0015] In one embodiment, the spacing between any two adjacent strip holes is consistent.
[0016] In one embodiment, the number of the strip holes is 8 to 15.
[0017] In one embodiment, the opening width of the strip hole is 18–22 mm.
[0018] In one embodiment, the outline of the stirring section is trapezoidal, triangular, rectangular, rod-shaped, or semi-circular.
[0019] In one embodiment, the length L1 of the stirring section is 15-20 mm.
[0020] In one embodiment, all the stirring sections are identical.
[0021] In one embodiment, two adjacent stirring sections located on the same long side are symmetrically arranged in the same strip-shaped hole.
[0022] In one embodiment, the stirring sections located on the two long sides of the same strip hole are arranged in a staggered manner.
[0023] In one embodiment, two adjacent stirring sections form a group, with the interval L2 between groups being consistent and the interval L3 within a group being consistent.
[0024] This utility model provides a wafer electroplating sieve plate, which optimizes the structure and parameters of the wafer electroplating sieve plate to adjust the uniformity of the height of wafer electroplating protrusions with and without notches. Attached Figure Description
[0025] Figure 1 The image shown is a top view of the wafer electroplating sieve plate of this utility model.
[0026] Figure 2The image shown is a perspective view of the wafer electroplating sieve plate of this utility model.
[0027] Figures 3-6 The diagram shown is a partial structural schematic of the stirring section in this invention.
[0028] Figure 7 The image shown is a Fullmap image for an example.
[0029] Figure 8 The image shown is a top view of an electroplating screen plate in the prior art.
[0030] Figure 9 Displayed as a scaled-down Fullmap image.
[0031] Explanation of reference numerals in the attached figures:
[0032] 1. Wafer electroplating sieve plate;
[0033] 11 slotted holes;
[0034] 12. Stirring section;
[0035] 121 Stirring the edge;
[0036] 2 Connecting ear. Detailed Implementation
[0037] The following specific embodiments illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification.
[0038] Please see Figures 1 to 9 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and are not intended to limit the scope of this invention. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of this invention, should still fall within the scope of the disclosed technical content. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention.
[0039] like Figure 1As shown, this utility model provides a wafer electroplating sieve plate. The wafer electroplating sieve plate 1 is provided with a plurality of strip holes 11. The length direction of any strip hole 11 is parallel to the linear reciprocating motion direction of the wafer electroplating sieve plate 1. Except for the strip hole 11 corresponding to the wafer notch, a plurality of stirring parts 12 are also formed in the other strip holes 11. The plurality of stirring parts 12 fill the corresponding strip holes 11 to form a hollow structure.
[0040] In the wafer electroplating process, the wafer electroplating screen 1 and the wafer are immersed in the electroplating solution. The wafer electroplating screen 1 reciprocates horizontally to adjust the uniformity of the wafer electroplating protrusion height between the notched and non-notched areas. Specifically, a stirring part 12 is provided in the strip hole 11 corresponding to the non-notched area of the wafer. When the wafer electroplating screen 1 reciprocates, the stirring part 12 stirs the electroplating solution, which helps to quickly replenish the metal cations on the surface to be electroplated at the non-notched area of the wafer, thereby increasing the electroplating protrusion height at the non-notched area. However, the wafer notch always corresponds to the strip hole 11 without the stirring part 12. Without the stirring of the stirring part 12, the metal cations on the surface to be electroplated at the wafer notch cannot be replenished quickly, resulting in a decrease in the electroplating protrusion height. Thus, the wafer electroplating protrusion height between the notched and non-notched areas achieves a uniform effect.
[0041] In a like Figures 1-2 In the specific embodiment shown, the wafer electroplating sieve plate 1 has a circular or near-circular structure.
[0042] In one specific embodiment, the diameter of the wafer plating screen 1 is at least 24 mm larger than the wafer. The wafer plating screen 1 is located directly below the wafer, and its reciprocating movement distance is 20-24 mm. The diameter of the wafer plating screen 1 is at least 24 mm larger than the wafer to ensure that it can fully cover the wafer during reciprocating motion, thereby controlling the concentration of metal cations on the entire wafer surface to be plating. The diameter of the wafer plating screen 1 must not exceed the size that the plating tank can accommodate.
[0043] In one specific embodiment, the thickness of the wafer plating screen 1 is 4.5–5.5 mm. Specifically, it can be 4.5–5.0 mm or 5.0–5.5 mm. The thickness of the wafer plating screen 1 is related to the height of the wafer plating screen 1 from the wafer; the closer the distance, the smaller the thickness of the wafer plating screen 1. Specifically, the thickness of the wafer plating screen 1 can be 4.5–5 mm or 5–5.5 mm.
[0044] In a more specific embodiment, the thickness of the wafer electroplating sieve plate 1 is the same as the thickness of the stirring section 12.
[0045] In a like Figures 1-2In the specific embodiment shown, the outline of the strip hole 11 is rectangular.
[0046] In a like Figures 1-2 In the specific embodiment shown, the spacing between any two adjacent strip holes 11 is consistent. In a more specific embodiment, the spacing between two adjacent strip holes 11 is 7-9 mm. For example, it can be 7-8 mm or 8-9 mm.
[0047] In one specific embodiment, the number of the strip-shaped holes 11 is 8 to 15. For example, it can be 8 to 9, 9 to 10, 10 to 11, 11 to 12, 12 to 13, 13 to 14, or 14 to 15. As an example, such as... Figure 1 As shown, the number of the strip holes 11 is 9.
[0048] In a like Figures 1-2 In the specific embodiment shown, the opening width of the strip-shaped hole 11 is 15-25 mm. The opening width of the strip-shaped hole 11 is related to the stirring effect; the larger the opening width of the strip-shaped hole 11, the smaller the stirring effect. For example, the width of the strip-shaped hole 11 is 15-17 mm, 17-19 mm, 19-21 mm, 21-23 mm, or 23-25 mm.
[0049] In one specific embodiment, the stirring section 12 has a stirring edge 121 perpendicular to the reciprocating motion direction. The stirring edge 121 can better shear the electroplating solution, resulting in a better stirring effect.
[0050] In a like Figure 2 In a more specific embodiment shown, the maximum width d of the stirring edge 121 is 15-25 mm. Specifically, it can be 15-18 mm, 18-20 mm, 20-22 mm, 22-24 mm, or 24-25 mm.
[0051] In a like Figures 2-7 In the specific embodiment shown, the outline of the stirring part 12 is trapezoidal, triangular, rectangular, rod-shaped, or semi-circular.
[0052] In one specific embodiment, the length L1 of the stirring section 12 is 15-20 mm. Specifically, it can be 15-17 mm, 17-19 mm, or 19-20 mm.
[0053] In a like Figure 2 In the specific embodiment shown, all the stirring parts 12 are identical. Specifically, all the stirring parts 12 have the same shape and size, ensuring that the stirring effect of each stirring part 12 on the wafer plating sieve plate 1 is consistent, thereby resulting in uniform wafer plating protrusion height at the non-notch areas of the wafer.
[0054] In a like Figure 2 In a more specific embodiment shown, two adjacent stirring sections 12 located on the same long side within the same strip-shaped hole 11 are symmetrically arranged. This ensures that the stirring effect of the stirring sections 12 is consistent during the reciprocating motion of the wafer plating sieve, resulting in uniform height of the wafer plating protrusions at the non-notch areas of the wafer.
[0055] In a like Figure 2 In a further specific embodiment shown, two adjacent stirring sections 12 constitute a group, with a consistent interval L2 between groups and a consistent interval L3 within each group. As an example, such as... Figure 2 As shown, the outline of the stirring section 12 is triangular, with two adjacent triangles forming a group. The interval L2 between groups is 25-28 mm, and the interval L3 within a group is 18-22 mm. During the electroplating process, parameters such as the flow rate, temperature, concentration, and current density of the electroplating solution are monitored in real time. Based on the monitoring data of the height of the wafer plating bumps, the number of stirring sections 12 can be adjusted by adjusting the length and interval of the stirring section 12 in each strip hole 11. For example, in areas where the height of the wafer plating bumps is low, the length and interval of the stirring section 12 in the strip hole 11 can be appropriately reduced to increase the number of stirring sections, thereby increasing the stirring area and improving the height of the wafer plating bumps at that location.
[0056] In a like Figure 2 In a more specific embodiment shown, the stirring portions 12 located on the two long sides of the same strip hole 11 are arranged in a staggered manner.
[0057] In one specific embodiment, the wafer electroplating screen 1 is connected to two sides by a motor that drives the wafer electroplating screen 1 to move along the length direction of the strip hole 11.
[0058] In a like Figure 1 In the specific embodiment shown, the wafer electroplating screen 1 has connecting lugs 2 on both sides of its edge, which are connected to the output shaft of the motor. The motor drives the wafer electroplating screen 1 to reciprocate along the length of the strip hole 11.
[0059] To more clearly illustrate the technical solution of this application, embodiments and comparative examples are used for further explanation.
[0060] Example
[0061] Adopting such Figure 2 The wafer plating sieve plate 1 shown is used for wafer plating tests on a horizontal electroplating machine. The copper anode is placed horizontally at the bottom of the electroplating tank, and the wafer is placed horizontally above the anode. The wafer plating sieve plate 1 is placed horizontally between the copper anode and the wafer and above the flow guide plate. The edge shielding ring covers the edge of the wafer and fits tightly.
[0062] The wafer diameter is 300mm. The diameter of the wafer electroplating sieve plate 1 is 320mm. The stirring section 12 has a right-angled triangular structure, and the width d of the stirring edge 121 is 17mm. The specific number of stirring edges 121 is as follows: Figure 2 As shown, there are 9 strip holes 11, and the opening width of the strip holes 11 is 22mm.
[0063] The opening diameter of the edge shielding ring is 280mm.
[0064] The guide plate is evenly provided with several circular guide holes. The diameter of the guide hole at the center of the guide plate is 0.8 mm, and the diameter of the guide hole at the edge of the guide plate is 1.6 mm. The diameters are distributed in a gradient.
[0065] Wafer plating testing steps:
[0066] 1) Surface treatment: Plasma cleaning is used to remove impurities or lithography machine residues from the wafer surface, especially in the windowed area.
[0067] 3) Pre-dip: The wafer is immersed in the electroplating solution for a period of time and rotated slowly to allow the plating solution to contact the windowed area and avoid the formation of bubbles in the windowed area.
[0068] 4) Electroplating: Electroplating is performed by applying an external electric field. The electroplating solution used is from Atotech. The electroplating solution uses Cu UF3, has a flow rate of 30 LPM, a reciprocating speed of 300 mm / s for the wafer electroplating sieve, a current density of 10 ASD, and a temperature of 25℃.
[0069] 5) Wash and dry.
[0070] After the electroplating test, an AOI device is used to scan the entire wafer surface to detect the height of the electroplated bumps, generating a Fullmap image (e.g., ...). Figure 7 As shown in the figure, the height of the electroplated protrusions is calculated by comparing it with a preset standard image, and the uniformity of the electroplated protrusion height of the wafer is 7.39% by calculation.
[0071] Electroplating protrusion height uniformity = (maximum electroplating protrusion height - minimum electroplating protrusion height) / average electroplating protrusion height / 2.
[0072] Comparative Example
[0073] Electroplating screens using existing technologies (such as...) Figure 8 (As shown) Replace the wafer plating sieve used in the previous embodiment and perform wafer plating test on a horizontal plating machine. The wafer plating equipment, wafer plating steps and parameter settings remain unchanged.
[0074] The shape and structure of the electroplating screen used in the comparative example are similar to those of the wafer electroplating screen 1 in the embodiment. The only difference is that the stirring part 12 is not provided in the strip hole 11, and the length direction of the strip hole 11 is perpendicular to the reciprocating motion direction of the electroplating screen.
[0075] After the electroplating test, an AOI device is used to scan the entire wafer surface to detect the height of the electroplated bumps, generating a Fullmap image (e.g., ...). Figure 9 As shown in the figure, the height of the electroplated protrusions is calculated by comparing it with a preset standard image, and the uniformity of the electroplated protrusion height of the wafer is 11.18% by calculation.
[0076] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A wafer electroplating screen plate, characterized by The wafer electroplating sieve plate (1) is provided with a plurality of strip-shaped holes (11). The length direction of any strip-shaped hole (11) is parallel to the linear reciprocating movement direction of the wafer electroplating sieve plate (1); in addition to the strip-shaped holes (11) corresponding to the wafer notch, a plurality of stirring portions (12) are also formed in the other strip-shaped holes (11); the plurality of stirring portions (12) fill the corresponding strip-shaped holes (11) to form a hollow structure.
2. The wafer electroplating screen plate of claim 1, wherein, The wafer electroplating sieve plate (1) is a circular structure or a circular-like structure; and / or, the diameter of the wafer electroplating sieve plate (1) is at least 24 mm larger than the wafer; and / or, the thickness of the wafer electroplating sieve plate (1) is 4.5-5.5 mm; and / or, the profile of the strip-shaped hole (11) is rectangular.
3. The wafer electroplating screen plate of claim 2, wherein, The thickness of the wafer electroplating sieve plate (1) is consistent with the thickness of the stirring portion (12).
4. The wafer electroplating screen plate of claim 1, wherein, The stirring portion (12) is formed with a stirring edge (121) perpendicular to the reciprocating movement direction.
5. The wafer electroplating screen plate of claim 4, wherein, The maximum width d of the stirring edge (121) is 15-25 mm.
6. The wafer electroplating screen plate of claim 1, wherein, The spacing between any two adjacent strip-shaped holes (11) is consistent; and / or, the number of strip-shaped holes (11) is 8-15; and / or, the opening width of the strip-shaped hole (11) is 15-25 mm.
7. The wafer electroplating screen plate of claim 1, wherein, The profile of the stirring portion (12) is trapezoidal, triangular, rectangular, rod-shaped or semicircular; and / or, the length L1 of the stirring portion (12) is 15-20 mm.
8. The wafer electroplating screen plate of claim 1, wherein, All the stirring portions (12) are the same.
9. The wafer electroplating screen plate of claim 8, wherein, In the same strip-shaped hole (11), the two adjacent stirring portions (12) located on the same long side are symmetrically arranged; and / or, in the same strip-shaped hole (11), the stirring portions (12) located on the two long sides are oppositely arranged.
10. The wafer electroplating screen plate of claim 9, wherein, Two adjacent stirring portions (12) constitute a group, the spacing L2 between groups is consistent, and the spacing L3 within a group is consistent.